Dear Sergey, I think, the temperature in a simulation with Nose thermostat is supposed to fluctuate around the target value, because your system exchanges energy with the thermostat. Your fluctuataions seem quite wild, but probably that's because your test system is quite small. I guess they'll be damped in a larger system. Moreover there is the MD.NoseMass parameter responsible for coupling to the thermostat. However, I can give you no hints about how to tune its value.
Consult the Nose paper (Progress of Theoretical Physics, Supplement No.103, 1991) - it is well readable. Best regards, Andrei Postnikov +-- Dr. habil. Andrei Postnikov ----- Tel. +49-541-969.2377 -- Fax .2351 ---+ | Institut fuer Festkoerperforschung - FZ Juelich, D-52425 Juelich, Germany | +-- [EMAIL PROTECTED] --------- http://www.home.uni-osnabrueck.de/apostnik/ --+ On Fri, 15 Jul 2005, Sergey Lisenkov wrote: | Dear Siesters, | | I am a little confused when perform MD with Nose thermostat. I put TargetTemperature = 500 K but in output file I see the next behaviour: | | siesta: Temp_ion = 56.381 K | siesta: Temp_ion = 39.006 K | siesta: Temp_ion = 251.629 K | siesta: Temp_ion = 394.578 K | siesta: Temp_ion = 216.338 K | siesta: Temp_ion = 24.889 K | siesta: Temp_ion = 204.911 K | siesta: Temp_ion = 416.811 K | siesta: Temp_ion = 281.607 K | siesta: Temp_ion = 36.181 K | siesta: Temp_ion = 58.008 K | siesta: Temp_ion = 343.699 K | siesta: Temp_ion = 482.636 K | siesta: Temp_ion = 222.906 K | siesta: Temp_ion = 49.991 K | siesta: Temp_ion = 342.534 K | siesta: Temp_ion = 555.130 K | siesta: Temp_ion = 327.737 K | siesta: Temp_ion = 35.523 K | siesta: Temp_ion = 97.661 K | siesta: Temp_ion = 453.434 K | siesta: Temp_ion = 590.339 K | siesta: Temp_ion = 239.125 K | siesta: Temp_ion = 60.871 K | siesta: Temp_ion = 482.552 K | | So, a question is : how to perform MD calculations with constant temperature (Nose thermostat)? | | Many thanks, | Best wishes, | Sergey | |
