[CPMD-list] NVT

[Martijn Zwijnenburg]

Hi,

I'm doing a NVT md run on a small cluster (see for inputfile below) 
and have some questions.

1) In my md run EHAM is not constant but rather varies from the third 
decimal on. However, since this run employs an NVT ensemble rather 
then an NVE I wonder if EHAM should still be conserved and thus stay 
constant?

2) The systems seems to cool down over time. I set the thermostat 
temperature at 1000K but the electron temperature cools down, after a 
small overshoot, to allready 600K after 200 steps. I guess this means 
my thermostat is not working properly?

Cheers,

Martijn

Inputfile:

! Si4O8 cluster MD
!
&CPMD
  MOLECULAR DYNAMICS
  STRUCTURE BONDS ANGLES DIHEDRALS
  CONVERGENCE
  1E-6 5E-6 1. 
  ISOLATED MOLECULE
  HESSIAN UNIT
  RESTART WAVEFUNCTION GEOMETRY LATEST
  NOSE IONS
  1000 800
  TIMESTEP
  5.0
  EMASS
  700
  TRAJECTORY XYZ
&END
&SYSTEM
  SYMMETRY
  0
  ANGSTROM
  CELL
  15 1.0 1.0 0 0 0
  ANGSTROM
  CUTOFF
  30.00
  POINT GROUP
  AUTO
&END
&ATOMS
*Si_ps.uspp BINARY new.f
  LMAX=P
 4
   0.000000000000      0.000000000000      0.000000000000
   0.471809914327      0.000000000000      3.182682023275
   3.653225710458     -0.034526749450      2.711038719844
   3.181409275132     -0.034559479116     -0.471644591443

*o_ps.uspp BINARY new.f
  LMAX=P
 8 
  0.000000000000      0.000000000000      1.626292446278
  2.098080331254     -0.016336484977      3.186832736955
  3.653206618118     -0.034138170947      1.084746035991
  1.555131813001     -0.018896584142     -0.475808582925
  4.871737465360     -0.049224011432      3.612939458029
 -0.432765838343      0.012873808042      4.399223302846
 -1.218511827443      0.015066749685     -0.901895052361
  4.086009030180     -0.046817197390     -1.688173543327

&END
&DFT
 FUNCTIONAL PW91
 GC-CUTOFF
 5E-5
&END
----------------------------------------------------------------------
---
Martijn Zwijnenburg
Lab. of Applied Organic Chemistry and Catalysis
Delft University of Technology
Julianalaan 136
2628 BL Delft
The Netherlands
Tel: 0031-(0)152782691
Fax: 0031-(0)152784700
e-mail: M.A.Zwijnenburg at tnw.tudelft.nl
web page: http://come.to/tock