TY  - JOUR
AU  - Lischka, Hans
AU  - Shepard, Ron
AU  - Müller, Thomas
AU  - Szalay, Péter G.
AU  - Pitzer, Russell M.
AU  - Aquino, Adelia J. A.
AU  - Araújo do Nascimento, Mayzza M.
AU  - Barbatti, Mario
AU  - Belcher, Lachlan T.
AU  - Blaudeau, Jean-Philippe
AU  - Borges, Itamar
AU  - Brozell, Scott R.
AU  - Carter, Emily A.
AU  - Das, Anita
AU  - Gidofalvi, Gergely
AU  - González, Leticia
AU  - Hase, William L.
AU  - Kedziora, Gary
AU  - Kertesz, Miklos
AU  - Kossoski, Fábris
AU  - Machado, Francisco B. C.
AU  - Matsika, Spiridoula
AU  - do Monte, Silmar A.
AU  - Nachtigallová, Dana
AU  - Nieman, Reed
AU  - Oppel, Markus
AU  - Parish, Carol A.
AU  - Plasser, Felix
AU  - Spada, Rene F. K.
AU  - Stahlberg, Eric A.
AU  - Ventura, Elizete
AU  - Yarkony, David R.
AU  - Zhang, Zhiyong
TI  - The generality of the GUGA MRCI approach in COLUMBUS for treating complex quantum chemistry
JO  - The journal of chemical physics
VL  - 152
IS  - 13
SN  - 1089-7690
CY  - Melville, NY
PB  - American Institute of Physics
M1  - FZJ-2021-00387
SP  - 134110 -
PY  - 2020
AB  - The core part of the program system COLUMBUS allows highly efficient calculations using variational multireference (MR) methods in the framework of configuration interaction with single and double excitations (MR-CISD) and averaged quadratic coupled-cluster calculations (MR-AQCC), based on uncontracted sets of configurations and the graphical unitary group approach (GUGA). The availability of analytic MR-CISD and MR-AQCC energy gradients and analytic nonadiabatic couplings for MR-CISD enables exciting applications including, e.g., investigations of π-conjugated biradicaloid compounds, calculations of multitudes of excited states, development of diabatization procedures, and furnishing the electronic structure information for on-the-fly surface nonadiabatic dynamics. With fully variational uncontracted spin-orbit MRCI, COLUMBUS provides a unique possibility of performing high-level calculations on compounds containing heavy atoms up to lanthanides and actinides. Crucial for carrying out all of these calculations effectively is the availability of an efficient parallel code for the CI step. Configuration spaces of several billion in size now can be treated quite routinely on standard parallel computer clusters. Emerging developments in COLUMBUS, including the all configuration mean energy multiconfiguration self-consistent field method and the graphically contracted function method, promise to allow practically unlimited configuration space dimensions. Spin density based on the GUGA approach, analytic spin-orbit energy gradients, possibilities for local electron correlation MR calculations, development of general interfaces for nonadiabatic dynamics, and MRCI linear vibronic coupling models conclude this overview.
LB  - PUB:(DE-HGF)16
C6  - 32268762
UR  - <Go to ISI:>//WOS:000524553600002
DO  - DOI:10.1063/1.5144267
UR  - https://juser.fz-juelich.de/record/889774
ER  -