Thermodynamic integration is used to calculate the difference in the Helmholtz energy function, , between two states.
The path must be continuous and reversible.
One has a continuously variable energy function such that
, and ,
where
- .
Isothermal integration
Ref. 1 Eq. 5:
Isobaric integration
Ref. 1 Eq. 6:
where is the Gibbs energy function and is the enthalpy.
Isochoric integration
Ref. 1 Eq. 7:
where is the internal energy.
See also
References
- C. Vega, E. Sanz, J. L. F. Abascal and E. G. Noya "Determination of phase diagrams via computer simulation: methodology and applications to water, electrolytes and proteins", Journal of Physics: Condensed Matter 20 153101 (2008) (section 4)