TEBEG - Revision history

Singraber at 21:05, 17 October 2025

2025-10-17T21:05:51Z

← Older revision		Revision as of 21:05, 17 October 2025
Line 10:		Line 10:
	</math>		</math>

	This temperature ~~ist~~ written to the {{FILE\|OUTCAR}} file.		This temperature is written to the {{FILE\|OUTCAR}} file.
	Depending on the type of thermostat this temperature has to be rescaled to obtain the real simulation temperature.		Depending on the type of thermostat this temperature has to be rescaled to obtain the real simulation temperature.

	*~~{{TAG\|Nose~~-Hoover thermostat}}:		*[[Nosé-Hoover thermostat]]:
	In this thermostat the number of degrees of freedom including ~~constraines~~ are already ~~acounted~~ for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is also taken into account in the {{TAG\|OUTCAR}} file.		In this thermostat the number of degrees of freedom including constraints are already accounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is also taken into account in the {{TAG\|OUTCAR}} file.

	*~~{{TAG\|~~Andersen thermostat}}:		*[[Andersen thermostat]]:
	Same as for ~~{{TAG\|Nose~~-Hoover thermostat}}.		Same as for [[Nosé-Hoover thermostat]].

	*~~{{TAG\|~~Langevin thermostat}}:		*[[Langevin thermostat]]:
	As for the ~~{{TAG\|Nose~~-Hoover thermostat}} and ~~{{TAG\|~~Andersen thermostat}} in this thermostat the number of degrees of freedom including ~~constraines~~ are already ~~acounted~~ for. The center of mass is not conserved in this method, hence this method has 3 degrees of freedom more than the ~~{{TAG\|Nose~~-Hoover thermostat}} and ~~{{TAG\|~~Andersen thermostat}}.		As for the [[Nosé-Hoover thermostat]] and [[Andersen thermostat]] in this thermostat the number of degrees of freedom including constraints are already accounted for. The center of mass is not conserved in this method, hence this method has 3 degrees of freedom more than the [[Nosé-Hoover thermostat]] and the [[Andersen thermostat]].

	== Related tags and articles ==		== Related tags and articles ==

Karsai at 12:22, 7 September 2022

2022-09-07T12:22:53Z

← Older revision		Revision as of 12:22, 7 September 2022
Line 1:		Line 1:
	{{TAGDEF\|TEBEG\|[real]\|0}}		{{TAGDEF\|TEBEG\|[real]\|0}}

	Description: {{TAG\|TEBEG}} sets the ~~start~~ temperature for an ab-initio molecular dynamics run ({{TAG\|IBRION}}=0) and other routines (e.g. {{TAG\|Electron-phonon interactions from Monte-Carlo sampling}}).		Description: {{TAG\|TEBEG}} sets the starting temperature (in K) for an ab-initio molecular dynamics run ({{TAG\|IBRION}}=0) and other routines (e.g. {{TAG\|Electron-phonon interactions from Monte-Carlo sampling}}).
	----		----
	If no initial velocities are supplied on the {{FILE\|POSCAR}} file, the velocities are set randomly according to a Maxwell-Boltzmann distribution at the initial temperature {{TAG\|TEBEG}}. Velocities are only used for molecular dynamics ({{TAG\|IBRION}}=0).		If no initial velocities are supplied on the {{FILE\|POSCAR}} file, the velocities are set randomly according to a Maxwell-Boltzmann distribution at the initial temperature {{TAG\|TEBEG}}. Velocities are only used for molecular dynamics ({{TAG\|IBRION}}=0).

Huebsch at 14:33, 7 April 2022

2022-04-07T14:33:11Z

← Older revision		Revision as of 14:33, 7 April 2022
Line 22:		Line 22:
	As for the {{TAG\|Nose-Hoover thermostat}} and {{TAG\|Andersen thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is not conserved in this method, hence this method has 3 degrees of freedom more than the {{TAG\|Nose-Hoover thermostat}} and {{TAG\|Andersen thermostat}}.		As for the {{TAG\|Nose-Hoover thermostat}} and {{TAG\|Andersen thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is not conserved in this method, hence this method has 3 degrees of freedom more than the {{TAG\|Nose-Hoover thermostat}} and {{TAG\|Andersen thermostat}}.

	== Related ~~Tags~~ and ~~Sections~~ ==		== Related tags and articles ==
	{{TAG\|TEEND}},		{{TAG\|TEEND}},
	{{TAG\|IBRION}},		{{TAG\|IBRION}},
Line 30:		Line 30:
	----		----

	[[Category:INCAR]][[Category:Molecular ~~Dynamics~~]]		[[Category:INCAR tag]][[Category:Molecular dynamics]]

Karsai at 13:52, 27 June 2019

2019-06-27T13:52:21Z

← Older revision		Revision as of 13:52, 27 June 2019
Line 20:		Line 20:

	*{{TAG\|Langevin thermostat}}:		*{{TAG\|Langevin thermostat}}:
	As for the {{TAG\|Nose-Hoover thermostat}} and {{TAG\|Andersen}} ~~thermostat~~ in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is not conserved in this method, hence this method has 3 degrees of freedom more than the {{TAG\|Nose-Hoover thermostat}} and {{TAG\|Andersen thermostat}}.		As for the {{TAG\|Nose-Hoover thermostat}} and {{TAG\|Andersen thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is not conserved in this method, hence this method has 3 degrees of freedom more than the {{TAG\|Nose-Hoover thermostat}} and {{TAG\|Andersen thermostat}}.

	== Related Tags and Sections ==		== Related Tags and Sections ==

Karsai at 13:52, 27 June 2019

2019-06-27T13:52:07Z

← Older revision		Revision as of 13:52, 27 June 2019
Line 7:		Line 7:
	'''Mind''': If {{TAG\|MDALGO}}>0 is used VASP defines the temperature as		'''Mind''': If {{TAG\|MDALGO}}>0 is used VASP defines the temperature as
	:<math>		:<math>
	T= \frac{1}{ k_B T 3 (N_{\rm ions}-N_{\rm constraints}-1)} \sum\limits_{n}^{N_{\rm ions}} M_n \| \vec v_n \|^2.		T= \frac{1}{ k_B T 3 (N_{\rm ions}-N_{\rm constraints})} \sum\limits_{n}^{N_{\rm ions}} M_n \| \vec v_n \|^2.
	</math>		</math>

Line 14:		Line 14:

	*{{TAG\|Nose-Hoover thermostat}}:		*{{TAG\|Nose-Hoover thermostat}}:
	In this thermostat the number of degrees of freedom including constraines are already acounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is also taken into account in the {{TAG\|OUTCAR}} file~~. Hence the temperature output in the {{TAG\|OUTCAR}} file is the actual simulation temperature~~.		In this thermostat the number of degrees of freedom including constraines are already acounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is also taken into account in the {{TAG\|OUTCAR}} file.

	*{{TAG\|Andersen thermostat}}:		*{{TAG\|Andersen thermostat}}:
Line 20:		Line 20:

	*{{TAG\|Langevin thermostat}}:		*{{TAG\|Langevin thermostat}}:
	As for the {{TAG\|Nose-Hoover thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center ~~of mass is also subtracted but the centre~~ of mass is not conserved in this method ~~since stochastic forces are acting on the atoms. Consequently~~, ~~the temperature in~~ the {{TAG\|~~OUTCAR~~}} ~~file has to be corrected to T=~~{{TAG\|~~TEBEG~~}}~~×(N<sub>ions</sub>-1)/N<sub>ions</sub>~~.		As for the {{TAG\|Nose-Hoover thermostat}} and {{TAG\|Andersen}} thermostat in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is not conserved in this method, hence this method has 3 degrees of freedom more than the {{TAG\|Nose-Hoover thermostat}} and {{TAG\|Andersen thermostat}}.


	== Related Tags and Sections ==		== Related Tags and Sections ==

Karsai at 10:34, 27 June 2019

2019-06-27T10:34:14Z

← Older revision		Revision as of 10:34, 27 June 2019
Line 14:		Line 14:

	*{{TAG\|Nose-Hoover thermostat}}:		*{{TAG\|Nose-Hoover thermostat}}:
	In this thermostat the number of degrees of freedom including constraines are already acounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is also taken into account in the {{TAG\|OUTCAR}} file. Hence the temperature output in the {{TAG\|OUTCAR}} file is the actual simulation temperature~~. This means that the real simulation temperature is: T={{TAG\|TEBEG}}×N<sub>ions</sub>/(N<sub>ions</sub>-1).~~		In this thermostat the number of degrees of freedom including constraines are already acounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is also taken into account in the {{TAG\|OUTCAR}} file. Hence the temperature output in the {{TAG\|OUTCAR}} file is the actual simulation temperature.
	Consequently, the temperature written by VASP (e.g. in the is incorrect and has to be corrected in accordance with the above. Usually the effect is rather small and subtle, but one should correct the error if very precise results are required; in that case the temperature should be specified according to: {{TAG\|TEBEG}}=T<sub>requested</sub>×(N<sub>ions</sub>-1)/N<sub>ions</sub>.

	*{{TAG\|Andersen thermostat}}:		*{{TAG\|Andersen thermostat}}:
Line 21:		Line 20:

	*{{TAG\|Langevin thermostat}}:		*{{TAG\|Langevin thermostat}}:
	As for the {{TAG\|Nose-Hoover thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is also subtracted but the centre of mass is not conserved in this method since stochastic forces are acting on the atoms. Consequently, the temperature in the {{TAG\|OUTCAR}} file has to be corrected to T={{TAG\|TEBEG}}×(N<sub>ions</sub>-1)/N<sub>ions</sub>		As for the {{TAG\|Nose-Hoover thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is also subtracted but the centre of mass is not conserved in this method since stochastic forces are acting on the atoms. Consequently, the temperature in the {{TAG\|OUTCAR}} file has to be corrected to T={{TAG\|TEBEG}}×(N<sub>ions</sub>-1)/N<sub>ions</sub>.

Karsai at 10:33, 27 June 2019

2019-06-27T10:33:53Z

← Older revision		Revision as of 10:33, 27 June 2019
Line 5:		Line 5:
	If no initial velocities are supplied on the {{FILE\|POSCAR}} file, the velocities are set randomly according to a Maxwell-Boltzmann distribution at the initial temperature {{TAG\|TEBEG}}. Velocities are only used for molecular dynamics ({{TAG\|IBRION}}=0).		If no initial velocities are supplied on the {{FILE\|POSCAR}} file, the velocities are set randomly according to a Maxwell-Boltzmann distribution at the initial temperature {{TAG\|TEBEG}}. Velocities are only used for molecular dynamics ({{TAG\|IBRION}}=0).

	'''Mind''': VASP defines the temperature as		'''Mind''': If {{TAG\|MDALGO}}>0 is used VASP defines the temperature as
	:<math>		:<math>
	T= \frac{1}{ k_B T 3 (N_{\rm ions}-N_{\rm constraints}-1)} \sum\limits_{n}^{N_{\rm ions}} M_n \| \vec v_n \|^2.		T= \frac{1}{ k_B T 3 (N_{\rm ions}-N_{\rm constraints}-1)} \sum\limits_{n}^{N_{\rm ions}} M_n \| \vec v_n \|^2.

Karsai at 10:33, 27 June 2019

2019-06-27T10:33:13Z

← Older revision		Revision as of 10:33, 27 June 2019
Line 7:		Line 7:
	'''Mind''': VASP defines the temperature as		'''Mind''': VASP defines the temperature as
	:<math>		:<math>
	T= \frac{1}{ k_B T 3 (N_{\rm ions}-N_{\rm constraints})-1} \sum\limits_{n}^{N_{\rm ions}} M_n \| \vec v_n \|^2.		T= \frac{1}{ k_B T 3 (N_{\rm ions}-N_{\rm constraints}-1)} \sum\limits_{n}^{N_{\rm ions}} M_n \| \vec v_n \|^2.
	</math>		</math>

Karsai at 10:32, 27 June 2019

2019-06-27T10:32:58Z

← Older revision		Revision as of 10:32, 27 June 2019
Line 7:		Line 7:
	'''Mind''': VASP defines the temperature as		'''Mind''': VASP defines the temperature as
	:<math>		:<math>
	T= \frac{1}{ k_B T 3 (N_{\rm ions}-N_{\rm constraints})} \sum\limits_{n}^{N_{\rm ions}} M_n \| \vec v_n \|^2.		T= \frac{1}{ k_B T 3 (N_{\rm ions}-N_{\rm constraints})-1} \sum\limits_{n}^{N_{\rm ions}} M_n \| \vec v_n \|^2.
	</math>		</math>

Karsai at 10:32, 27 June 2019

2019-06-27T10:32:47Z

← Older revision		Revision as of 10:32, 27 June 2019
Line 14:		Line 14:

	*{{TAG\|Nose-Hoover thermostat}}:		*{{TAG\|Nose-Hoover thermostat}}:
	In this thermostat the number of degrees of freedom including constraines are already acounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is ~~not~~ taken into account in the {{TAG\|OUTCAR}} file. This means that the real simulation temperature is: T={{TAG\|TEBEG}}×N<sub>ions</sub>/(N<sub>ions</sub>-1).		In this thermostat the number of degrees of freedom including constraines are already acounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is also taken into account in the {{TAG\|OUTCAR}} file. Hence the temperature output in the {{TAG\|OUTCAR}} file is the actual simulation temperature. This means that the real simulation temperature is: T={{TAG\|TEBEG}}×N<sub>ions</sub>/(N<sub>ions</sub>-1).
	Consequently, the temperature written by VASP (e.g. in the is incorrect and has to be corrected in accordance with the above. Usually the effect is rather small and subtle, but one should correct the error if very precise results are required; in that case the temperature should be specified according to: {{TAG\|TEBEG}}=T<sub>requested</sub>×(N<sub>ions</sub>-1)/N<sub>ions</sub>.		Consequently, the temperature written by VASP (e.g. in the is incorrect and has to be corrected in accordance with the above. Usually the effect is rather small and subtle, but one should correct the error if very precise results are required; in that case the temperature should be specified according to: {{TAG\|TEBEG}}=T<sub>requested</sub>×(N<sub>ions</sub>-1)/N<sub>ions</sub>.

			*{{TAG\|Andersen thermostat}}:
			Same as for {{TAG\|Nose-Hoover thermostat}}.

	*{{TAG\|Langevin thermostat}}:		*{{TAG\|Langevin thermostat}}:
	As for the {{TAG\|Nose-Hoover thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is not conserved in this method since stochastic forces are acting on the atoms. ~~Hence~~ the temperature ~~output~~ in the {{TAG\|OUTCAR}} file ~~is the actual simulation temperature.~~		As for the {{TAG\|Nose-Hoover thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is also subtracted but the centre of mass is not conserved in this method since stochastic forces are acting on the atoms. Consequently, the temperature in the {{TAG\|OUTCAR}} file has to be corrected to T={{TAG\|TEBEG}}×(N<sub>ions</sub>-1)/N<sub>ions</sub>

	*{{TAG\|Andersen thermostat}}:
	~~Same as for {{TAG\|Langevin thermostat}}.~~

← Older revision		Revision as of 10:34, 27 June 2019
Line 14:		Line 14:

	*{{TAG\|Nose-Hoover thermostat}}:		*{{TAG\|Nose-Hoover thermostat}}:
	In this thermostat the number of degrees of freedom including constraines are already acounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is also taken into account in the {{TAG\|OUTCAR}} file. Hence the temperature output in the {{TAG\|OUTCAR}} file is the actual simulation temperature~~. This means that the real simulation temperature is: T={{TAG\|TEBEG}}×N<sub>ions</sub>/(N<sub>ions</sub>-1).~~		In this thermostat the number of degrees of freedom including constraines are already acounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is also taken into account in the {{TAG\|OUTCAR}} file. Hence the temperature output in the {{TAG\|OUTCAR}} file is the actual simulation temperature.
	Consequently, the temperature written by VASP (e.g. in the is incorrect and has to be corrected in accordance with the above. Usually the effect is rather small and subtle, but one should correct the error if very precise results are required; in that case the temperature should be specified according to: {{TAG\|TEBEG}}=T<sub>requested</sub>×(N<sub>ions</sub>-1)/N<sub>ions</sub>.

	*{{TAG\|Andersen thermostat}}:		*{{TAG\|Andersen thermostat}}:
Line 21:		Line 20:

	*{{TAG\|Langevin thermostat}}:		*{{TAG\|Langevin thermostat}}:
	As for the {{TAG\|Nose-Hoover thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is also subtracted but the centre of mass is not conserved in this method since stochastic forces are acting on the atoms. Consequently, the temperature in the {{TAG\|OUTCAR}} file has to be corrected to T={{TAG\|TEBEG}}×(N<sub>ions</sub>-1)/N<sub>ions</sub>		As for the {{TAG\|Nose-Hoover thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is also subtracted but the centre of mass is not conserved in this method since stochastic forces are acting on the atoms. Consequently, the temperature in the {{TAG\|OUTCAR}} file has to be corrected to T={{TAG\|TEBEG}}×(N<sub>ions</sub>-1)/N<sub>ions</sub>.

← Older revision		Revision as of 10:32, 27 June 2019
Line 14:		Line 14:

	*{{TAG\|Nose-Hoover thermostat}}:		*{{TAG\|Nose-Hoover thermostat}}:
	In this thermostat the number of degrees of freedom including constraines are already acounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is ~~not~~ taken into account in the {{TAG\|OUTCAR}} file. This means that the real simulation temperature is: T={{TAG\|TEBEG}}×N<sub>ions</sub>/(N<sub>ions</sub>-1).		In this thermostat the number of degrees of freedom including constraines are already acounted for in the potential energy term. In this this method the center of mass is conserved. This lowers the degrees of freedom by one which is also taken into account in the {{TAG\|OUTCAR}} file. Hence the temperature output in the {{TAG\|OUTCAR}} file is the actual simulation temperature. This means that the real simulation temperature is: T={{TAG\|TEBEG}}×N<sub>ions</sub>/(N<sub>ions</sub>-1).
	Consequently, the temperature written by VASP (e.g. in the is incorrect and has to be corrected in accordance with the above. Usually the effect is rather small and subtle, but one should correct the error if very precise results are required; in that case the temperature should be specified according to: {{TAG\|TEBEG}}=T<sub>requested</sub>×(N<sub>ions</sub>-1)/N<sub>ions</sub>.		Consequently, the temperature written by VASP (e.g. in the is incorrect and has to be corrected in accordance with the above. Usually the effect is rather small and subtle, but one should correct the error if very precise results are required; in that case the temperature should be specified according to: {{TAG\|TEBEG}}=T<sub>requested</sub>×(N<sub>ions</sub>-1)/N<sub>ions</sub>.

			*{{TAG\|Andersen thermostat}}:
			Same as for {{TAG\|Nose-Hoover thermostat}}.

	*{{TAG\|Langevin thermostat}}:		*{{TAG\|Langevin thermostat}}:
	As for the {{TAG\|Nose-Hoover thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is not conserved in this method since stochastic forces are acting on the atoms. ~~Hence~~ the temperature ~~output~~ in the {{TAG\|OUTCAR}} file ~~is the actual simulation temperature.~~		As for the {{TAG\|Nose-Hoover thermostat}} in this thermostat the number of degrees of freedom including constraines are already acounted for. The center of mass is also subtracted but the centre of mass is not conserved in this method since stochastic forces are acting on the atoms. Consequently, the temperature in the {{TAG\|OUTCAR}} file has to be corrected to T={{TAG\|TEBEG}}×(N<sub>ions</sub>-1)/N<sub>ions</sub>

	*{{TAG\|Andersen thermostat}}:
	~~Same as for {{TAG\|Langevin thermostat}}.~~