RESTART
MOLINFO STRUCTURE=ref.pdb MOLTYPE=rna

g1: TORSION ATOMS=@gamma-1
c1: TORSION ATOMS=@chi-1
puck1: PUCKERING ATOMS=@sugar-1

#J coupling
n1: TORSION ATOMS=10,9,27,28
n2: TORSION ATOMS=28,27,25,26
n3: TORSION ATOMS=26,25,6,7
x:  TORSION ATOMS=29,25,9,28
#h4'-h5'
n4: TORSION ATOMS=7,6,3,4
#h4'-h5''
n5: TORSION ATOMS=7,6,3,5
chi: TORSION ATOMS=8,9,11,24
chi1: TORSION ATOMS=10,9,11,12

j1: MATHEVAL ARG=n1 FUNC=9.67*cos(x)*cos(x)-2.03*cos(x) PERIODIC=NO
j2: MATHEVAL ARG=n2 FUNC=9.67*cos(x)*cos(x)-2.03*cos(x) PERIODIC=NO
j3: MATHEVAL ARG=n3 FUNC=9.67*cos(x)*cos(x)-2.03*cos(x) PERIODIC=NO

#jh4'-h5'
j4: MATHEVAL ARG=n4 FUNC=8.313*cos(x)*cos(x)-0.99*cos(x)+1.373+0.27*cos(x)*sin(x) PERIODIC=NO

#jh4'-h5''
j5: MATHEVAL ARG=n5 FUNC=8.313*cos(x)*cos(x)-0.99*cos(x)+1.373-4.752*cos(x)*sin(x) PERIODIC=NO

#jc4-jh'
j6: MATHEVAL ARG=c1 FUNC=3.6*cos(x-(pi/180.0)*68.6)*cos(x-(pi/180.0)*68.6)+1.8*cos(x-(pi/180.0)*68.6)+0.4 PERIODIC=NO

#jc8-h1'
j7: MATHEVAL ARG=chi1 FUNC=4.2*cos(x+(pi/180.0)*(60.0-68.9))*cos(x+(pi/180.0)*(60.0-68.9))-0.5*cos(x+(pi/180.0)*(60.0-68.9))+0.3 PERIODIC=NO


MAXENT ...
LABEL=res
ARG=j1,j2,j3,j4,j5,j6,j7 
KAPPA=0.001,0.001,0.001,0.001,0.001,0.001,0.001 
TAU=3.0,3.0,3.0,3.0,3.0,3.0,3.0 
ERROR_TYPE=LAPLACE
SIGMA=0.5
TSTART=50
TEND=100
TYPE=EQUAL AT=6.0,5.0,3.4,3.0,3.4,3.6,3.9
PACE=10
FMT=%f
TEMP=300
... MAXENT

PRINT ...
ARG=j1,j2,j3,j4,j5,j6,j7 
STRIDE=10 FILE=colvar
FMT=%8.3f
... PRINT