- Isoenthalpic–isobaric ensemble
The

**isoenthalpic-isobaric ensemble**(constantenthalpy and constantpressure ensemble) is a statistical mechanical ensemble that maintains constant enthalpy $H\; ,$ and constant pressure $P\; ,$ applied. It is also called the $NpH$-ensemble, where the number of particles $N\; ,$ is also kept as a constant. It was developed by physicist H. C. Andersen in 1980. [*Andersen, H. C. "Journal of Chemical Physics" 72, 2384-2393 (1980).*] The ensemble adds another degree of freedom, which represents the variable volume $V\; ,$ of a system to which the coordinates of all particles are relative. The volume $V\; ,$ becomes a dynamicalvariable withpotential energy andkinetic energy given by $PV\; ,$. [*Hwee, Chiang Soo. [*] . The enthalpy $H=E+PV\; ,$ is a*http://dynamicslab.mpe.nus.edu.sg/dynamics/project0304/thesis0304/Mechanical%20behavior%20of%20bio-cell%20in%20living%20system%20using%20molecular%20dynamics.pdf "Mechanical behavior of peptides in living systems using molecular dynamics."*]conserved quantity . [*[*]*http://www.fisica.uniud.it/~ercolessi/md/md/node43.html Other Statistical Ensembles*]**References**

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