# 4.3. GUI¶

The manual for graphical viewer GV, and LUSCUS can be found online: http://www.molcas.org/GV/, http://luscus.sourceforge.net/.

## 4.3.1. Writing LUSCUS/MOLDEN input¶

By default the GUESSORB, SCF, MBPT2, RASSCF, SLAPAF, LOCALISATION, and MCLR modules generate input in Molden format. The SCF, MBPT2, RASSCF, and LOCALISATION modules generate input for molecular orbital analysis, SLAPAF for geometry optimization analysis, minimum energy paths, Saddle optimization paths and IRC TS analysis, and the MCLR module generates input for analysis of harmonic frequencies.

The generic name of the input file and the actual name are different for the nodes as a reflection on the data generated by each module. Hence, the actual names (generic name) for the Molden files in each module are

• GUESSORB module: $Project.guessorb.molden (MD_GSS) • SCF module:$Project.scf.molden (MD_SCF)
• MBPT2 module: $Project.mp2.molden (MD_MP2) • RASSCF module:$Project.rasscf.molden (MD_CAS) for the state-averaged natural orbitals, and $Project.rasscf.x.molden (MD_CAS.x) for the state-specific natural spin orbitals, where x is the index of a CI root. • SLAPAF module:$Project.geo.molden (MD_GEO) for geometry optimizations, $Project.mep.molden (MD_MEP) for minimum energy paths,$Project.irc.molden (MD_IRC) for IRC analysis of a TS, and $Project.saddle.molden (MD_SADDLE) for Saddle method TS optimizations. • LOCALISATION module:$Project.local.molden (MD_LOC)
• MCLR module: \$Project.freq.molden (MD_FREQ)

Files in MOLDEN format can be visualized by Molden program, or by Molcas GUI program LUSCUS.

Note, the MOLDEN code cannot handle cases in which some shells, with the same angular momentum, are Cartesian and some are real spherical harmonics. All shells for a give angular momentum have to be either Cartesian or real spherical harmonics, otherwise no MOLDEN file for orbitals will be generated.

For further details with respect to Molden consult http://www.cmbi.ru.nl/molden/.

For further details with respect to LUSCUS consult http://luscus.sourceforge.net/.