diff --git a/regtest/rt10-mpi/COLVAR.reference b/regtest/rt10-mpi/COLVAR.reference
index d9b5a49b617d8f2bbe2b7ea2c0a5306588f3b3fb..7504a6077aaf93e5b0e56fe050a85827d094b8f1 100644
--- a/regtest/rt10-mpi/COLVAR.reference
+++ b/regtest/rt10-mpi/COLVAR.reference
@@ -1,6 +1,6 @@
 #! FIELDS time mu1 vol md.bias
  0.000000  1.163 127.933  0.000
- 0.050000  1.131 127.933  0.950
- 0.100000  1.098 127.933  1.759
- 0.150000  1.080 127.933  2.578
- 0.200000  1.087 127.933  3.651
+ 0.050000  1.131 127.933  0.000
+ 0.100000  1.098 127.933  0.948
+ 0.150000  1.080 127.933  1.866
+ 0.200000  1.087 127.933  2.901
diff --git a/regtest/rt10-mpi/HILLS.reference b/regtest/rt10-mpi/HILLS.reference
index b64cc24463e4cf7508dd73de432d9c15a9a86970..02cc0bd9a167a21972835abce12a5d5ba32c0014 100644
--- a/regtest/rt10-mpi/HILLS.reference
+++ b/regtest/rt10-mpi/HILLS.reference
@@ -1,7 +1,6 @@
 #! FIELDS time mu1 vol sigma_mu1 sigma_vol height biasf
 #! SET multivariate false
-                      0      1.162646040831079       127.932640011072                    0.1                    0.2                      1                      1
-                   0.05      1.130546273059004       127.932640011072                    0.1                    0.2                      1                      1
-                    0.1      1.097928292824707       127.932640011072                    0.1                    0.2                      1                      1
-                   0.15      1.080244153391634       127.932640011072                    0.1                    0.2                      1                      1
-                    0.2      1.086854650075657       127.932640011072                    0.1                    0.2                      1                      1
+      0.050000      1.130546    127.932640      0.100000      0.200000      1.000000      1.000000
+      0.100000      1.097928    127.932640      0.100000      0.200000      1.000000      1.000000
+      0.150000      1.080244    127.932640      0.100000      0.200000      1.000000      1.000000
+      0.200000      1.086855    127.932640      0.100000      0.200000      1.000000      1.000000
diff --git a/regtest/rt10-mpi/forces.0.reference b/regtest/rt10-mpi/forces.0.reference
index 6aa58604076185752396848e0c810efd560f8a2e..0f6df3cbbd41c5c7f6d18daa3a1004ccd40f4bb6 100644
--- a/regtest/rt10-mpi/forces.0.reference
+++ b/regtest/rt10-mpi/forces.0.reference
@@ -109,8 +109,9 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  1.638054   0.000271   1.808470
-X   2.101762   0.027021  -2.208387
+  0.000000   0.000000   0.000000
+X   0.000000   0.000000   0.000000
+X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -119,7 +120,6 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -2.101762  -0.027021   2.208387
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -219,8 +219,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  4.042953   0.006377   5.109348
-X   5.542322  -0.220112  -6.230532
+  1.498973   0.002364   1.894352
+X   2.054883  -0.081609  -2.310045
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -229,7 +229,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -5.542322   0.220112   6.230532
+X  -2.054883   0.081609   2.310045
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -329,8 +329,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  5.105457   0.066644   7.835592
-X   7.543893  -0.861902  -9.345749
+  2.617465   0.034167   4.017150
+X   3.867602  -0.441880  -4.791378
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -339,7 +339,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -7.543893   0.861902   9.345749
+X  -3.867602   0.441880   4.791378
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -439,8 +439,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  3.594713   0.120538   7.261337
-X   5.779554  -1.058339  -8.214299
+  1.570522   0.052663   3.172461
+X   2.525074  -0.462386  -3.588808
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -449,7 +449,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -5.779554   1.058339   8.214299
+X  -2.525074   0.462386   3.588808
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
diff --git a/regtest/rt10-mpi/forces.1.reference b/regtest/rt10-mpi/forces.1.reference
index 6aa58604076185752396848e0c810efd560f8a2e..0f6df3cbbd41c5c7f6d18daa3a1004ccd40f4bb6 100644
--- a/regtest/rt10-mpi/forces.1.reference
+++ b/regtest/rt10-mpi/forces.1.reference
@@ -109,8 +109,9 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  1.638054   0.000271   1.808470
-X   2.101762   0.027021  -2.208387
+  0.000000   0.000000   0.000000
+X   0.000000   0.000000   0.000000
+X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -119,7 +120,6 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -2.101762  -0.027021   2.208387
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -219,8 +219,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  4.042953   0.006377   5.109348
-X   5.542322  -0.220112  -6.230532
+  1.498973   0.002364   1.894352
+X   2.054883  -0.081609  -2.310045
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -229,7 +229,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -5.542322   0.220112   6.230532
+X  -2.054883   0.081609   2.310045
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -329,8 +329,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  5.105457   0.066644   7.835592
-X   7.543893  -0.861902  -9.345749
+  2.617465   0.034167   4.017150
+X   3.867602  -0.441880  -4.791378
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -339,7 +339,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -7.543893   0.861902   9.345749
+X  -3.867602   0.441880   4.791378
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -439,8 +439,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  3.594713   0.120538   7.261337
-X   5.779554  -1.058339  -8.214299
+  1.570522   0.052663   3.172461
+X   2.525074  -0.462386  -3.588808
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -449,7 +449,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -5.779554   1.058339   8.214299
+X  -2.525074   0.462386   3.588808
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
diff --git a/regtest/rt10-mpi/plumed.dat b/regtest/rt10-mpi/plumed.dat
index 35c22198e6dae9f06cbbb3614509fad03fed3edc..ebde2b3ad545381b2ec56d5450d712200623fa1f 100644
--- a/regtest/rt10-mpi/plumed.dat
+++ b/regtest/rt10-mpi/plumed.dat
@@ -1,7 +1,7 @@
 mu1: DISTANCE ATOMS=1,10
 vol: VOLUME 
 
-METAD ARG=mu1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md
+METAD ARG=mu1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md FMT=%14.6f
 
 PRINT ...
   STRIDE=1
diff --git a/regtest/rt10-restart/HILLS.reference b/regtest/rt10-restart/HILLS.reference
index df5a9f3dca322a036f8f9d936ea5f834f65b54e2..e1d4b5d7818cf251c61e0ad2a6204d11d48e2304 100644
--- a/regtest/rt10-restart/HILLS.reference
+++ b/regtest/rt10-restart/HILLS.reference
@@ -7,7 +7,7 @@
                     0.2      1.086854650075657       127.932640011072                    0.1                    0.2                      1                      1
 #! FIELDS time mu1 vol sigma_mu1 sigma_vol height biasf
 #! SET multivariate false
-                   0.05      1.130546273059004       127.932640011072                    0.1                    0.2                      1                      1
-                    0.1      1.097928292824707       127.932640011072                    0.1                    0.2                      1                      1
-                   0.15      1.080244153391634       127.932640011072                    0.1                    0.2                      1                      1
-                    0.2      1.086854650075657       127.932640011072                    0.1                    0.2                      1                      1
+      0.050000      1.130546    127.932640      0.100000      0.200000      1.000000      1.000000
+      0.100000      1.097928    127.932640      0.100000      0.200000      1.000000      1.000000
+      0.150000      1.080244    127.932640      0.100000      0.200000      1.000000      1.000000
+      0.200000      1.086855    127.932640      0.100000      0.200000      1.000000      1.000000
diff --git a/regtest/rt10-restart/plumed.dat b/regtest/rt10-restart/plumed.dat
index ceaf41d5d2e7c4752eb201fc4d0f25a439b30e58..f65aa3fd23aae46c5355b5e1ff7b750dbedafc5c 100644
--- a/regtest/rt10-restart/plumed.dat
+++ b/regtest/rt10-restart/plumed.dat
@@ -2,7 +2,7 @@ RESTART
 mu1: DISTANCE ATOMS=1,10
 vol: VOLUME 
 
-METAD ARG=mu1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md
+METAD ARG=mu1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md FMT=%14.6f
 
 PRINT ...
   STRIDE=1
diff --git a/regtest/rt10/HILLS.reference b/regtest/rt10/HILLS.reference
index ddf3a9e63e174568471b025ef5e0d3942be8ac9f..02cc0bd9a167a21972835abce12a5d5ba32c0014 100644
--- a/regtest/rt10/HILLS.reference
+++ b/regtest/rt10/HILLS.reference
@@ -1,6 +1,6 @@
 #! FIELDS time mu1 vol sigma_mu1 sigma_vol height biasf
 #! SET multivariate false
-                   0.05      1.130546273059004       127.932640011072                    0.1                    0.2                      1                      1
-                    0.1      1.097928292824707       127.932640011072                    0.1                    0.2                      1                      1
-                   0.15      1.080244153391634       127.932640011072                    0.1                    0.2                      1                      1
-                    0.2      1.086854650075657       127.932640011072                    0.1                    0.2                      1                      1
+      0.050000      1.130546    127.932640      0.100000      0.200000      1.000000      1.000000
+      0.100000      1.097928    127.932640      0.100000      0.200000      1.000000      1.000000
+      0.150000      1.080244    127.932640      0.100000      0.200000      1.000000      1.000000
+      0.200000      1.086855    127.932640      0.100000      0.200000      1.000000      1.000000
diff --git a/regtest/rt10/plumed.dat b/regtest/rt10/plumed.dat
index 35c22198e6dae9f06cbbb3614509fad03fed3edc..ebde2b3ad545381b2ec56d5450d712200623fa1f 100644
--- a/regtest/rt10/plumed.dat
+++ b/regtest/rt10/plumed.dat
@@ -1,7 +1,7 @@
 mu1: DISTANCE ATOMS=1,10
 vol: VOLUME 
 
-METAD ARG=mu1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md
+METAD ARG=mu1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md FMT=%14.6f
 
 PRINT ...
   STRIDE=1
diff --git a/regtest/rt11-mpi/COLVAR.reference b/regtest/rt11-mpi/COLVAR.reference
index d038a56db15acba45ade5e965ba4516fba2155ab..d526b2413b220075d72d9225c95cc93b57c88f4d 100644
--- a/regtest/rt11-mpi/COLVAR.reference
+++ b/regtest/rt11-mpi/COLVAR.reference
@@ -1,6 +1,6 @@
 #! FIELDS time d1 vol md.bias
  0.000000  1.163 127.933  0.000
- 0.050000  1.131 127.933  0.949
- 0.100000  1.098 127.933  1.719
- 0.150000  1.080 127.933  2.468
- 0.200000  1.087 127.933  3.435
+ 0.050000  1.131 127.933  0.000
+ 0.100000  1.098 127.933  0.948
+ 0.150000  1.080 127.933  1.824
+ 0.200000  1.087 127.933  2.781
diff --git a/regtest/rt11-mpi/HILLS.reference b/regtest/rt11-mpi/HILLS.reference
index 6d6dfc5cd9668ae4694dea1573d9d21549dc4474..c7916b811f55e77097aaa2d1267d811ed7fab241 100644
--- a/regtest/rt11-mpi/HILLS.reference
+++ b/regtest/rt11-mpi/HILLS.reference
@@ -1,7 +1,6 @@
 #! FIELDS time d1 vol sigma_d1 sigma_vol height biasf
 #! SET multivariate false
-                      0      1.162646040831079       127.932640011072                    0.1                    0.2      1.111111111111111                     10
-                   0.05      1.130546273059004       127.932640011072                    0.1                    0.2      1.065099172242622                     10
-                    0.1      1.097928292824707       127.932640011072                    0.1                    0.2      1.029189249157886                     10
-                   0.15      1.080244153391634       127.932640011072                    0.1                    0.2     0.9954423252507112                     10
-                    0.2      1.086854650075657       127.932640011072                    0.1                    0.2     0.9534672200896532                     10
+      0.050000      1.130546    127.932640      0.100000      0.200000      1.111111     10.000000
+      0.100000      1.097928    127.932640      0.100000      0.200000      1.065174     10.000000
+      0.150000      1.080244    127.932640      0.100000      0.200000      1.024390     10.000000
+      0.200000      1.086855    127.932640      0.100000      0.200000      0.981665     10.000000
diff --git a/regtest/rt11-mpi/forces.0.reference b/regtest/rt11-mpi/forces.0.reference
index b04e0302600193b77f810ff18a2f339d1e004eef..bfa86a4fd2d71982aabfef26b42d4c5b70ef9f39 100644
--- a/regtest/rt11-mpi/forces.0.reference
+++ b/regtest/rt11-mpi/forces.0.reference
@@ -109,8 +109,9 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  1.626689  -0.010586   1.797052
-X   2.101110   0.027013  -2.207702
+  0.000000   0.000000   0.000000
+X   0.000000   0.000000   0.000000
+X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -119,7 +120,6 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -2.101110  -0.027013   2.207702
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -219,8 +219,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  3.960245  -0.013384   5.010011
-X   5.455894  -0.216680  -6.133373
+  1.488048  -0.008475   1.883404
+X   2.054765  -0.081605  -2.309912
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -229,7 +229,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -5.455894   0.216680   6.133373
+X  -2.054765   0.081605   2.309912
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -329,8 +329,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  4.943026   0.036672   7.601393
-X   7.345582  -0.839245  -9.100071
+  2.564989   0.012893   3.947768
+X   3.820888  -0.436543  -4.733505
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -339,7 +339,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -7.345582   0.839245   9.100071
+X  -3.820888   0.436543   4.733505
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -439,8 +439,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  3.489935   0.079062   7.089751
-X   5.674247  -1.039055  -8.064629
+  1.539029   0.020875   3.141279
+X   2.525564  -0.462475  -3.589505
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -449,7 +449,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -5.674247   1.039055   8.064629
+X  -2.525564   0.462475   3.589505
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
diff --git a/regtest/rt11-mpi/forces.1.reference b/regtest/rt11-mpi/forces.1.reference
index b04e0302600193b77f810ff18a2f339d1e004eef..bfa86a4fd2d71982aabfef26b42d4c5b70ef9f39 100644
--- a/regtest/rt11-mpi/forces.1.reference
+++ b/regtest/rt11-mpi/forces.1.reference
@@ -109,8 +109,9 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  1.626689  -0.010586   1.797052
-X   2.101110   0.027013  -2.207702
+  0.000000   0.000000   0.000000
+X   0.000000   0.000000   0.000000
+X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -119,7 +120,6 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -2.101110  -0.027013   2.207702
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -219,8 +219,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  3.960245  -0.013384   5.010011
-X   5.455894  -0.216680  -6.133373
+  1.488048  -0.008475   1.883404
+X   2.054765  -0.081605  -2.309912
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -229,7 +229,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -5.455894   0.216680   6.133373
+X  -2.054765   0.081605   2.309912
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -329,8 +329,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  4.943026   0.036672   7.601393
-X   7.345582  -0.839245  -9.100071
+  2.564989   0.012893   3.947768
+X   3.820888  -0.436543  -4.733505
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -339,7 +339,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -7.345582   0.839245   9.100071
+X  -3.820888   0.436543   4.733505
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -439,8 +439,8 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 108
-  3.489935   0.079062   7.089751
-X   5.674247  -1.039055  -8.064629
+  1.539029   0.020875   3.141279
+X   2.525564  -0.462475  -3.589505
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
@@ -449,7 +449,7 @@ X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
-X  -5.674247   1.039055   8.064629
+X  -2.525564   0.462475   3.589505
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
 X   0.000000   0.000000   0.000000
diff --git a/regtest/rt11-mpi/plumed.dat b/regtest/rt11-mpi/plumed.dat
index d6b219e74733158915642ea22ab0202486a38a4a..6b8f1d964dfb8063a9e1819e3823c96be119a387 100644
--- a/regtest/rt11-mpi/plumed.dat
+++ b/regtest/rt11-mpi/plumed.dat
@@ -1,7 +1,7 @@
 d1: DISTANCE ATOMS=1,10
 vol: VOLUME 
 
-METAD ARG=d1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md TEMP=300 GRID_MIN=0.0,120.0 GRID_MAX=2.0,130.0 BIASFACTOR=10 GRID_BIN=100,100 
+METAD ARG=d1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md TEMP=300 GRID_MIN=0.0,120.0 GRID_MAX=2.0,130.0 BIASFACTOR=10 GRID_BIN=100,100 FMT=%14.6f
 
 PRINT ...
   STRIDE=1
diff --git a/regtest/rt11/HILLS.reference b/regtest/rt11/HILLS.reference
index 2c699aa1999cc9a96202cb5680d374c8cff2545a..c7916b811f55e77097aaa2d1267d811ed7fab241 100644
--- a/regtest/rt11/HILLS.reference
+++ b/regtest/rt11/HILLS.reference
@@ -1,6 +1,6 @@
 #! FIELDS time d1 vol sigma_d1 sigma_vol height biasf
 #! SET multivariate false
-                   0.05      1.130546273059004       127.932640011072                    0.1                    0.2      1.111111111111111                     10
-                    0.1      1.097928292824707       127.932640011072                    0.1                    0.2      1.065174260458566                     10
-                   0.15      1.080244153391634       127.932640011072                    0.1                    0.2      1.024390181269172                     10
-                    0.2      1.086854650075657       127.932640011072                    0.1                    0.2     0.9816652626232401                     10
+      0.050000      1.130546    127.932640      0.100000      0.200000      1.111111     10.000000
+      0.100000      1.097928    127.932640      0.100000      0.200000      1.065174     10.000000
+      0.150000      1.080244    127.932640      0.100000      0.200000      1.024390     10.000000
+      0.200000      1.086855    127.932640      0.100000      0.200000      0.981665     10.000000
diff --git a/regtest/rt11/plumed.dat b/regtest/rt11/plumed.dat
index d6b219e74733158915642ea22ab0202486a38a4a..6b8f1d964dfb8063a9e1819e3823c96be119a387 100644
--- a/regtest/rt11/plumed.dat
+++ b/regtest/rt11/plumed.dat
@@ -1,7 +1,7 @@
 d1: DISTANCE ATOMS=1,10
 vol: VOLUME 
 
-METAD ARG=d1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md TEMP=300 GRID_MIN=0.0,120.0 GRID_MAX=2.0,130.0 BIASFACTOR=10 GRID_BIN=100,100 
+METAD ARG=d1,vol SIGMA=0.1,0.2 HEIGHT=1.0 PACE=10 LABEL=md TEMP=300 GRID_MIN=0.0,120.0 GRID_MAX=2.0,130.0 BIASFACTOR=10 GRID_BIN=100,100 FMT=%14.6f
 
 PRINT ...
   STRIDE=1
diff --git a/regtest/rt31/HILLS.reference b/regtest/rt31/HILLS.reference
index bebe8daae0fa630e0cf04c16ffde6df6ca1e51a5..d4206a5ecf991dbf31eb6700145af393d4426cfd 100644
--- a/regtest/rt31/HILLS.reference
+++ b/regtest/rt31/HILLS.reference
@@ -4,14 +4,14 @@
 #! SET max_t1 pi
 #! SET min_t2 -pi
 #! SET max_t2 pi
-                   0.05     -3.083261300014765     -3.024982280130822     0.3068765374446373     0.1317156819534852     0.2219038336879245                      1                      1
-                    0.1     -3.068159974124374     -2.840724239954784     0.3273752284905043     0.1287946985205632     0.2191728672385122                      1                      1
-                   0.15     -3.040634447344844     -3.001399224210649      0.309012487480437     0.1368894742549938     0.2128896103566548                      1                      1
-                    0.2     -3.085485424299153     -3.048472374414181      0.312030154944296     0.1369706721914347     0.2146164336102369                      1                      1
-                   0.25     -3.102321573753832      3.033460965705072     0.3107788468383018     0.1355310104840249     0.2100200249057109                      1                      1
-                    0.3      3.068176644482511     -2.954097708713826     0.2875605380481934     0.1285158240590685     0.1985684006304812                      1                      1
-                   0.35      2.967036219353802      2.833197690878928     0.3036270845480871     0.1282463447576107      0.203873623452256                      1                      1
-                    0.4      3.126411602927766     -2.930178200023739      0.314328841908631     0.1353785688455022     0.2122610191413208                      1                      1
-                   0.45     -3.114958785366576      3.085118956120171     0.3056075480858189     0.1265084850028464     0.2145894252982076                      1                      1
-                    0.5      2.971974894171093     -3.038293528216732     0.3041333929431195      0.129670884404099     0.2177895007541573                      1                      1
-                   0.55     -3.137597902359275     -3.047325071464987     0.2927564500621495     0.1294356748447308      0.196081564199542                      1                      1
+      0.050000     -3.083261     -3.024982      0.306877      0.131716      0.221904      1.000000      1.000000
+      0.100000     -3.068160     -2.840724      0.327375      0.128795      0.219173      1.000000      1.000000
+      0.150000     -3.040634     -3.001399      0.309012      0.136889      0.212890      1.000000      1.000000
+      0.200000     -3.085485     -3.048472      0.312030      0.136971      0.214616      1.000000      1.000000
+      0.250000     -3.102322      3.033461      0.310779      0.135531      0.210020      1.000000      1.000000
+      0.300000      3.068177     -2.954098      0.287561      0.128516      0.198568      1.000000      1.000000
+      0.350000      2.967036      2.833198      0.303627      0.128246      0.203874      1.000000      1.000000
+      0.400000      3.126412     -2.930178      0.314329      0.135379      0.212261      1.000000      1.000000
+      0.450000     -3.114959      3.085119      0.305608      0.126508      0.214589      1.000000      1.000000
+      0.500000      2.971975     -3.038294      0.304133      0.129671      0.217790      1.000000      1.000000
+      0.550000     -3.137598     -3.047325      0.292756      0.129436      0.196082      1.000000      1.000000
diff --git a/regtest/rt31/plumed.dat b/regtest/rt31/plumed.dat
index 7b3cf503d64d85e803a47441affa8adffdf637fb..3308cba87753f58c48fe406c3a151fc98fed7e8a 100644
--- a/regtest/rt31/plumed.dat
+++ b/regtest/rt31/plumed.dat
@@ -1,4 +1,4 @@
 TORSION ATOMS=2,5,6,7  LABEL=t1
 TORSION ATOMS=5,6,7,9  LABEL=t2
 PRINT ARG=t1,t2 STRIDE=1 FILE=colvar FMT=%8.4f
-METAD ARG=t1,t2 SIGMA=0.01 ADAPTIVE=GEOM HEIGHT=1.0 PACE=10 LABEL=md  
+METAD ARG=t1,t2 SIGMA=0.01 ADAPTIVE=GEOM HEIGHT=1.0 PACE=10 LABEL=md  FMT=%14.6f
diff --git a/src/bias/MetaD.cpp b/src/bias/MetaD.cpp
index 49f8b6a36d1ba24b09c7d134996153d825dbdda3..f4be0260d8493916ff122b7896e6ea41143543da 100644
--- a/src/bias/MetaD.cpp
+++ b/src/bias/MetaD.cpp
@@ -152,6 +152,7 @@ private:
   void   finiteDifferenceGaussian(const vector<double>&, const Gaussian&);
   vector<unsigned> getGaussianSupport(const Gaussian&);
   bool   scanOneHill(IFile *ifile,  vector<Value> &v, vector<double> &center, vector<double>  &sigma, double &height, bool &multivariate  );
+  std::string fmt;
 
 public:
   MetaD(const ActionOptions&);
@@ -171,6 +172,7 @@ void MetaD::registerKeywords(Keywords& keys){
   keys.add("compulsory","HEIGHT","the heights of the Gaussian hills");
   keys.add("compulsory","PACE","the frequency for hill addition");
   keys.add("compulsory","FILE","HILLS","a file in which the list of added hills is stored");
+  keys.add("optional","FMT","specify format for HILLS files (useful for decrease the number of digits in regtests)");
   keys.add("optional","BIASFACTOR","use well tempered metadynamics and use this biasfactor.  Please note you must also specify temp");
   keys.add("optional","TEMP","the system temperature - this is only needed if you are doing well-tempered metadynamics");
   keys.add("optional","GRID_MIN","the lower bounds for the grid");
@@ -232,6 +234,8 @@ isFirstStep(true)
   // parse the sigma
   parseVector("SIGMA",sigma0_);
 
+  parse("FMT",fmt);
+
   // if you use normal sigma you need one sigma per argument 
   if (adaptive_==FlexibleBin::none){
          if( sigma0_.size()!=getNumberOfArguments() ) error("number of arguments does not match number of SIGMA parameters");
@@ -363,6 +367,7 @@ isFirstStep(true)
   hillsOfile_.link(*this);
   if(plumed.getRestart()) hillsOfile_.open(ifilesnames[mw_id_],"aw");
   else hillsOfile_.open(ifilesnames[mw_id_]);
+  if(fmt.length()>0) hillsOfile_.fmtField(fmt);
   hillsOfile_.addConstantField("multivariate");
   hillsOfile_.setHeavyFlush();
 // output periodicities of variables