GIBBS: isothermal-isobaric thermodynamics of solids from energy curves using a quasi-harmonic Debye model

M.A. Blanco ∗, E. Francisco, V. Luaña

 Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, 33006 Oviedo, Spain

 Received 11 July 2003

Abstract:

Given the energy of a solid (E) as a function of the molecular volume (V ), the gibbs program uses a quasi-harmonic Debye model to generate the Debye temperature Θ(V ), obtains the non-equilibrium Gibbs function G (V ;p, T ), and minimizes G to derive the thermal equation of state (EOS) V (p, T ) and the chemical potential G(p, T ) of the corresponding phase. Other macroscopic properties are also derived as a function of p and T from standard thermodynamic relations. The program focuses in obtaining as much thermodynamical information as possible from a minimum set of (E, V ) data, making it suitable to analyse the output of costly electronic structure calculations, adding thermal effects at a low computational cost. Any of three analytical EOS widely used in the literature can be fitted to the p − V (p, T ) data, giving an alternative set of isothermal bulk moduli and their pressure derivatives that can be fed to the Debye model machinery.

Program summary

 Title of the program: gibbs

 Catalogue number: ADSY Program summary 

URL: http://cpc.cs.qub.ac.uk/summaries/ADSY

 Program obtainable from: CPC Program Library, Queen’s University of Belfast, N. Ireland

 Licensing provisions: Persons requesting the program must sign the standard CPC non-profit use license 

Computers on which the program has been tested: Intel Pentium, Alpha, Sun Sparc/Ultra/Blade Operating system under which the program has been tested: Unix, GNU/Linux

 Programming language used: Fortran 77

 Memory required to execute with typical data: 700 KB 

No. of bits in a word: 32 

No. of processors used: 1

 No. of bytes in distributed program, including test data, etc.: 277 497 

No. of lines in distributed program, including test data, etc.: 7390 Distribution format: tar gzip file Keywords: Quasi-harmonic Debye model, equation of state

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http://www.sciencedirect.com.sci-hub.cc/science/article/pii/S0010465503005472