Molcas Forum

vkj

Member

Registered: 2019-04-10

Posts: 31

[SOLVED] XMS-CASPT2 affects SS-CASPT2

Dear Molcas Users,

If I do a computation using XMS-CASPT2 (XMultistate keyword) my single-state CASPT2 energies are different than when i jut use multistate CASPT2(multistate keyword). Is this an expected behaviour ? I would have expected the multi-state energies and states to be different but the SS-CASPT2 to be unaffected.  Both caspt2 calculations are done with IPEA=0 and IMAG=0.2 . In both the calculations the RASSCF energies are the same.

Program Details:
OpenMolcas  version 18.09 , tag: 541-gc159f88

configuration info
------------------
C Compiler ID: Intel
C flags: -std=gnu99
Fortran Compiler ID: Intel
Fortran flags: -fpp -i8 -r8 -heap-arrays
Definitions: _MOLCAS_;_I8_;_LINUX_;_GA_;_MOLCAS_MPP_;SCALAPACK;_MKL_
Parallel: ON (GA=ON)

Bothe calculations were run using 1 core, which as reflected in output where each module reports running in SERIAL mode.

Last edited by vkj (2019-09-29 14:57:52)

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,202

Re: [SOLVED] XMS-CASPT2 affects SS-CASPT2

Yes, XMS uses a different H-zero Hamiltonian and gives different SS energies.