MOLPRO

21 MULTIREFERENCE RAYLEIGH SCHRÖDINGER PERTURBATION THEORY 174
rs2,analytical,ignore 1.8250 102.1069 -76.22789382
rs2,analytical,exact 1.8261 102.1168 -76.22789441
rs2,numerical 1.8261 102.1168 -76.22789441
rs2c,numerical 1.8260 102.1187 -76.22787681
MS-CASPT2 geometry optimization for the second excited 3 B 2 state if H 2 O:
***
memory,8,m
gthresh,energy=1.d-12
!
basis=vdz
R=2.0
R0=R
Theta=100
step=0.001
geometry={O
H1,O,R;
H2,O,R,H1,THETA}
hf;accu,12
multi !state averaged casscf for various triplet states
closed,2
wf,10,1,2
state,3
wf,10,2,2
state,2
wf,10,3,2
state,3
canonical,2140.2
rs2,mix=3,root=2,shift=0.2
wf,10,3,2
state,3
optg,gradient=1.d-5
e_opt(1)=msenergy(2)
r_opt(1)=r
theta_opt(1)=theta
method(1)=’rs2,analytical’
!optimized second 3B2 state
!3B2 wavefunction symmetry
!include 3 states
!geometry optimization using analytical gradients
!optimized ms-caspt2 energy
!optimized bond distance
!optimized bond angle
rs2,mix=3,shift=0.2
wf,10,3,2
!3B2 wavefunction symmetry
state,3
!include 3 states
optg,variable=msenergy(2),gradient=1.d-5,fourpoint
!geometry optimization using numerical gradients
e_opt(2)=msenergy(2)
r_opt(2)=r
theta_opt(2)=theta
method(2)=’rs2,numerical’
!optimized ms-caspt2 energy
!optimized bond distance
!optimized bond angle
table,method,r_opt,theta_opt,e_opt
digits,,4,4,8
http:
//www.molpro.net/info/current/examples/h2o_mscaspt2_opt.com
This produces the table
METHOD R_OPT THETA_OPT E_OPT