[CPMD-list] Bad results during the heating phase of a md run

[Reinaldo Pis Diez]

	Dear folks,

		I'm trying to reproduce some older results on sodium clusters 
(Röthlisberger and Andreoni, JCP 94 (1991) 8129) following a different 
strategy. I want to let the clusters evolve at a given temperature for 
a long period saving the coordinates every several ps and then 
optimize each previously saved geometry.
		I'm using version 3.9.2 of CPMD, Goedecker pseudos for sodium with 
Zion = 9 and PBE xc functional. I've made some previous tests with the 
sodium dimer and found that 60 Ry for PW cutoff are ok to reproduce 
the bond distance, for example. Then, I turn to the sodium hexamer. I 
use a simulated annealing procedure to optimize the wavefunction 
(na6_wfn.inp and na6_wfn.out files) and it seems to be alright. Then, 
the hexamer is allowed to heat up to 600 K. The lattice of the (cubic) 
cell was 15 A and the PW cutoff was 60 Ry as said above. The md run 
diverges from the second time step. I increased the lattice cell and 
the PW cutoff to 25 A and 70 Ry, respectively, to see where the 
problem is but I got the same results (na6_md_ini.inp and 
na6_md_ini.out files). I can see from the output that EKINC is going 
large at the very beginning of the run but I don't know if this could 
be a clue and how to handle it to  get the simulation running. Any 
help will be very appreciated. The input and output files are appended.
		Sorry for the long mail but I cannot figure out how to explain my 
problem in few words.
		Thanks in advance.
		Regards,

						Reinaldo
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