Output Files

The output file of pgm is a plain text file, containing a comma-separated value (CSV) table, with the name of the file following the rule of <property><grid_type>_<unit>.

• <property>

  the abbreviation of the property in lower case, i.e., g for Gibbs free energy, as will be explained in details in the table below.

• <grid_type>

  • <tp> the index of the columns is the list of the pressures, and the index of the rows is the list of the temperatures, specified by the user

  • <tv> the index of the columns is the list of the volumes, and the index of the rows is the list of the temperatures, specified by the user

• <unit>

  by default, the outputs are using energy unit of eV, temperature unit of K, pressure unit of GPa, volume unit of ų.

Output parameters

Table 5: A list of the important output properties as functions of temperature and pressure or volume.

Property name	Output	Description
Free Energy \(F\)	ftv_ev_a3	Helmholtz free energy (T, V) result. Free energy in unit of ev, volumes in ang3
Pressure \(P\)	ptv_gpa_K_a3	Pressure (T, V) result. Pressure in the unit of GPa, temperature in Kelvin, volumes in ang3.
Entropy \(S\)	stv_ev_K_a3	Entropy (T, V) result. entropy in unit of ev/k, temperature in Kelvin, volumes in ang3.
Internal energy \(U\)	utp_ev_K_gpa	Internal energy (T, P) result. Internal energy in the unit of eV, temperature in Kelvin, pressure in GPa.
Enthalpy \(H\)	htp_ev_K_gpa	Enthalpy (T, P) result. Enthalpy in the unit of eV, temperature in Kelvin, pressure in GPa.
Gibbs free energy \(G\)	gtp_ev_K_gpa	Gibbs Free Energy (T, P) result. Gibbs Free Energy in the unit of eV, temperature in Kelvin, pressure in GPa.
Thermal expansion coefficient \(α\)	alpha_K_gpa	Thermal expansion coefficient (T, P) result. Thermal expansion coefficient in the unit of 1/K, temperature in Kelvin, pressure in GPa.
Isothermal bulk modulus \(B_T\)	bt_gpa_K_gpa	Isothermal bulk modulus (T, P) result. Isothermal bulk modulus in the unit of GPa, temperature in Kelvin, pressure in GPa.
Grüneisen parameter \(γ\)	gamma_K_gpa	Grüneisen parameter (T, P) result. Temperature in the unit of Kelvin, pressure in GPa.
Adiabatic bulk modulus \(B_S\)	bs_gpa_K_gpa	Adiabatic bulk modulus (T, P) result. Adiabatic bulk modulus in the unit of GPa, temperature in the unit of Kelvin, pressure in GPa.
Volumetric heat capacity \(C_V\)	cv_jmol_K_gpa	Volumetric heat capacity (T, P) result. Volumetric heat capacity in the unit of J·mol/K, temperature in the unit of Kelvin, pressure in GPa.
Isobaric heat capacity \(C_P\)	cp_jmol_K_gpa	Isobaric heat capacity (T, P) result. Isobaric heat capacity in the unit of J·mol/K, temperature in the unit of Kelvin, pressure in GPa.