[molpro-user] Questions about spin orbit coupling in molpro?

[Hao, Hongxia]

Dear Molpro users,

I am trying to do some calculations with spin-orbit coupling effect.
In the following is the example file in Molpro. I have a few questions
regarding this.

1. How did Molpro calculate SO integrals? Or what are those ECP-SO
for? We want to include the SO effect as accurate as possible, but
when we use ECP, does that mean it only calculates the SO integrals
for the pseudo-cores, but without the valence electrons? How could we
have an explicit treatment of the valence Hamiltonian then?

2. What are these core polarization potentials for? When should we use that?

3. For those ECP-SO parameters, where could we get them? And those
corresponding weights? I don't have ideas how they generate that
basis.

Thanks in advance for any help!
Sincerely
Laura

***,I
memory,5,M;
gprint,orbitals,civector,basis;
gthresh,energy=1.d-8,coeff=1.d-8;
geometry={I};

basis={
!
! Iodine-ECP (Dirac-Fock) with SO-coupling and cpp
!

ecp,I,46,4,3;
1; 2,   1.00000000,       0.00000000;
     ! lokal term = 0
2; 2,   3.50642001,      83.09814545; 2,   1.74736492,
5.06370919;    ! s-terme
4; 2,   2.99860773, 1/3* 81.88444526; 2,   3.01690894, 2/3*
83.41280402;    ! p-terms with weights
    2,   1.59415934, 1/3*  2.32392477; 2,   1.19802939, 2/3*  2.72079843;
4; 2,   1.03813792, 2/5*  6.40131754; 2,   1.01158599, 3/5*
6.21328827;    ! d-terms with weights
    2,   2.04193864, 2/5* 19.11604172; 2,   1.99631017, 3/5* 19.08465909;
4; 2,   2.64971585,-3/7* 24.79106489; 2,   2.75335574,-4/7*
24.98147319;    ! f-terms with weights
    2,   0.49970082,-3/7*  0.27936581; 2,   0.79638982,-4/7*  0.70184261;
4; 2,   2.99860773,-2/3* 81.88444526; 2,   3.01690894, 2/3*
83.41280402;    ! ECP-SO for p-terms
    2,   1.59415934,-2/3*  2.32392477; 2,   1.19802939, 2/3*  2.72079843;
4; 2,   1.03813792,-2/5*  6.40131754; 2,   1.01158599, 2/5*
6.21328827;    ! ECP-SO for d-terms
    2,   2.04193864,-2/5* 19.11604172; 2,   1.99631017, 2/5* 19.08465909;
4; 2,   2.64971585, 2/7* 24.79106489; 2,   2.75335574,-2/7*
24.98147319;    ! ECP-SO for f-terms
    2,   0.49970082, 2/7*  0.27936581; 2,   0.79638982,-2/7*  0.70184261;
!
! Iodine-basis
!
s,I,0.2027624,0.4080619,0.8212297,1.6527350,3.3261500;
c,1.5,-0.4782372,-0.5811680,0.2617769,0.4444120,-0.1596560;
s,I,0.05,0.1007509;
p,I,0.2027624,0.4080619,0.8212297,1.6527350,3.3261500;
c,1.5,0.4251859,0.2995618,0.0303167,-0.2064228,0.0450858;
p,I,0.05,0.1007509,0.01;  ! diffuse p-Funktion wegen evt. neg. Part.Ldg
d,I,0.2,0.4;
f,I,0.3;
}

{cpp,init,1;       ! core polarization potential
I,2,1.028,,,1.23}  ! Iod-Atom,form of cut-off function, static polarizability
                           ! 1.23 =  exponential-factor of cut-off function

{hf;occ,1,1,1,,1;wf,7,5,1}      !scf for 2Pz

{multi;occ,1,2,2,,2              !casscf with larger active space
wf,7,2,1;wf,7,3,1;wf,7,5,1}     !average 2P states
{ci;wf,7,2,1;noexc;save,5010.2}
{ci;wf,7,3,1;noexc;save,5110.2}
{ci;wf,7,5,1;noexc;save,5210.2}
{ci;wf,7,2,1;save,6010.2}
{ci;wf,7,3,1;save,6110.2}
{ci;wf,7,5,1;save,6210.2}

text,casscf,  occ,1,2,2,,2
{ci;hlsmat,ecp,5010.2,5110.2,5210.2}

text,mrci, occ,1,2,2,,2
{ci;hlsmat,ecp,6010.2,6110.2,6210.2}