state,3 weight,1,1,0
and
state,8 weight,1,1,0,0,0,0,0,0
For some geometries there is a large difference between the NACMEs and the difference of the energy gradients. However, the energies, the sum of energy gradients and the CI vectors are equal. The discrepancy in the NACME falls of inversely as the geometry is distorted away from the bad point so it looks like a conical intersection (all energies are well separated though).
the input files are
***,h3
geomtyp=xyz
gprint,orbitals,civector
geomtyp=xyz
geometry={nosym;noorient;
3
a comment
H1, 0.0000000000000000E+00, 0.0000000000000000E+00, 0.0000000000000000E+00
H2, 0.0000000000000000E+00, 0.1073111972324246E+01, 0.0000000000000000E+00
H3, 0.0000000000000000E+00,-0.8305234896369812E+00, 0.4101461803747558E+01
}
basis=6-311G
hf,3,1,0
multi
wf,3,1,1
!!!!! Uncomment one or other !!!!
! state,8
! weight,1,1,0,0,0,0,0,0
! state,3
! weight,1,1,0
start,3003.2
accuracy,gradient=1.0e-8,step=1.0e-4,energy=1.0e-8
noextra
maxiter, 40;
iterations;dont,internal,1,5;end;
iterations;uncouple,5,to,10;end;
orbitals,3000.2
cpmcscf, grad,1.1,spin=0.5,accu=1.d-11,save=5101.1
cpmcscf, grad,2.1,spin=0.5,accu=1.d-11,save=5102.1
cpmcscf, dgrad,1.1,2.1, accu=1.d-11,save=5103.1
cpmcscf, nacm, 1.1,2.1, accu=1.d-11,save=5104.1forces;samc,5101.1; forces;samc,5102.1; forces;samc,5103.1; forces;samc,5104.1;
