Running CRYSTAL

Restart Phonon calculations

Following files are needed. Put a RESTART in FREQCALC block in the input file.

• FILENAME.d12 Input file
• FILENAME.f13 Binary. Reducible density matrix at central point. To exploit maximum symmetry in numerical second derivatives calculations. (fort.13)
• FILENAME.f20 SCF guess (fort.20)
• FILENAME.f9 Binary. Wave function computed at the equilibrium geometry. Full symmetry exploited by default. When those data are used to restart, file fort.9 is read as file fort.20 (SCF guess). (fort.9)
• FILENAME.FREQINFO Formatted. Contains information on the Hessian. Updated at each point, it is necessary to restart a frequency calculation. (FREQINFO.DAT)
• FILENAME.gui Relaxed structure (fort.34)

Info

It is tricky to restart a phonon calculation from MPPcrystal using Pcrystal. I don’t know why… I’m waiting for the email of developer

FREQINFO.DAT

FREQINFO.DAT is different from MPPcrystal and Pcrystal.

MPPCrystal

line	content	information	comment
first line	some integers	system information	generate at the beginning
second line	T or F	progress ?	generate at the beginning, update during phonon
first block	floats with lots of zeros	should be force constants	generate at the beginning, update during phonon calculations
last block	lots of float numbers	don’t know	only write at the end of phonon calculation

Pcrystal

line	content	information	comment
first line	some integers	system information	generate at the beginning
second line	T or F	progress ?	generate at the beginning, update during phonon
first block	floats with lots of zeros	should be force constants	generate at the beginning, update during phonon calculations
big blocks	flots and block of integers	unknown	generate at the beginning, not updating
last block	lots of float numbers	unknown	write at the end of phonon calculation

• Possible restart strategy is to take the first two lines + first block of FREQINFO.DAT from MPPcrystal and copy the big blocks from Pcrystal and then restart phonon

Restart CPHF calculation

CPHF is used for Raman calculations. A static CPHF/KS run can be restarted from a previous run (even an incomplete run) by using the RESTART keyword. This works for both the first– and second–order perturbed iterative procedures. Every CPHF/KS run writes the necessary information for a restart to file fort.31. This file must be provided as file fort.32 before running the new calculation with the RESTART keyword. GUESSP (SCF guess from density matrix of a previous run, input block 3) is not applied by default, but its use is recommended.