HfO pec with Marci

[Jie Hui]

Hi,

Im trying to scan the potential energy surface of the HfO molecule with the following input file

gprint,orbitals=4,civector

spherical

basis={

hf = cc-pVTZ-PP

o = aug-cc-pVTZ

}

geometry = {hf;o,hf,r}

dr = 0.05

i = 1

do r=1.4,2.1,dr,ang

!if (i.eq.1) then

{rhf

wf,20,1,0

!save,2100.2,ignore_error

}

{multi

!start,2100.2,ignore_error

occ,8,3,3,1

frozen,4,1,1,0

maxit,200

wf,20,1,0;state,2;lquant,0,2

wf,20,4,0;state,2;lquant,0,0

wf,20,2,0;state,1

wf,20,3,0;state,1

wf,20,1,2;state,2;lquant,0,2

wf,20,4,2;state,2;lquant,0,0

wf,20,2,2;state,1

wf,20,3,2;state,1

wf,20,1,4;state,2;lquant,0,2

wf,20,4,4;state,2;lquant,0,0

wf,20,2,4;state,1

wf,20,3,4;state,1

expec2,lzlz

!save,3501.1

}

{ci

occ,8,3,3,1

core,4,1,1,0

wf,20,1,0

!ref,3

state,2

!save,4410.1

maxiter,100,100

}

sigma_plus_1(i) = energy(1)

delta_1_1(i) = energy(2)

{ci

occ,8,3,3,1

core,4,1,1,0

wf,20,1,2

maxiter,100,100

}

delta_1_3(i) = energy(1)

{ci

occ,8,3,3,1

core,4,1,1,0

wf,20,4,0

maxiter,100,100

}

delta_4_1(i) = energy(1)

{ci

occ,8,3,3,1

core,4,1,1,0

wf,20,4,2

maxiter,100,100

}

delta_4_3(i) = energy(1)

{ci

occ,8,3,3,1

core,4,1,1,0

wf,20,2,2

ref,3

maxiter,100,100

}

pi_2_3(i) = energy(1)

rr(i) = r

i=i+1

enddo

{table,sigma_plus_1

save,sigma_plus_1.txt

}

{table,delta_1_1

save,delta_1_1.txt

}

{table,delta_1_3

save,delta_1_3.txt

}

{table,delta_4_1

save,delta_4_1.txt

}

{table,delta_4_3

save,delta_4_3.txt

}

{table,pi_2_3

save,pi_2_3.txt

}

put,molden,hfo_mrci.molden

The sigma and delta states seem fine but the pi state has a jump which I don't quite understand what leads to this, is it because the number of states in the multi step is not sufficient or rhf, if it's the rhf step what should I do to avoid this, thank you very much