Setting up an excited state calculation

In order to set up an excited state calculation using NRLMOL, the following files are needed after you run a ground state calculation:

1. RUNS
2. REPMAT
3. GRPMAT
4. ISYMGEN
5. SYMBOL
6. HAMOLD
7. VMOLD
8. NRLMOL_INPUT.DAT
9. XMOL.DAT

Put all these files in a separate directory. You will need to modify the files RUNS and SYMBOL, and run NRLMOL again with this files as input files (no CLUSTER file is needed).

The file RUNS must contain this:

-1 1 ITBEG, NCALC
1 4 START: 0=SCR.NUC, 1=HAM, 2=POT, 3=LSF, 4=WFUNC
0 START HAMILTONIAN IS INTERPOLATED: 0=NO, 1=YES

In SYMBOL, you must remove other geometries that may have been created.

Scroll down until you find the line:

1 CALCULATION SETUP BY ISETUP

This is the first line of the first geometry, it ends at the line:

EXTRABASIS = 0

If any ohter geometries were created during the ground state calcultation, the will begin after this with

N NEW CALCULATION CREATED BY UPDATE

Where N is the number of geometry, the also end with the EXTRABASIS line.

So remove them all from SYMBOL and just keep the first geometry.

Also, set the variable EXCITEDV in NRLMOL_INPUT.DAT to 'Y' for NRLMOL to execute an excited state calculation.

One more file needed (OCCEXC) is a separate file that is not created during a ground state calculation, I have a java program that generates it, it needs the files EVALUES and SUMMARY to be present in the directory where it will be created (so you might consider copying these files as well).

Compile the java file with: javac create_occexc.java
Once it compiles, it will create a file called create_occexc.class
Run it with:java create_occexc 0 0 1 1
Where the four numbers given as arguments are:

1. The level where the hole will be created, HOMO is referenced as 0 (example: HOMO-1 must be specified as -1).
2. The level where the particle will move, LUMO is referenced as 0 (example: LUMO+2 must be specified as 2).
3. The spin for the hole state.
4. The spin for the particle state.