Build a system

Create an empty system

The first step is to create an empty system, ordinarily using create().

system = profess.System.create(box_vectors, energy_cutoff, ['a','ev'])

The arguments provided to create() are the lattice vectors (in the rows of an array-like object or list), the plane wave cutoff energy, and the units for the previous variables (given as a list).

create	Create empty system, using a plane wave energy cutoff to determine the grid dimensions.
create_from_grid_shape	Create empty system with a specific grid dimensions.

Add ions

The standard method is add_ions(), which uses a pseudopotential file. A method for adding bare Coulomb ions is also available.

add_ions	Add ions to the system.
add_coulomb_ions	Add Coulomb ions to the system.

Add electrons

add_electrons

Add electrons to the system.

Add energy functionals

Kinetic

add_huang_carter_functional	Add Huang Carter kinetic energy functional.
add_luo_karasiev_trickey_functional	Add Luo-Karasiev-Trickey kinetic energy functional.
add_generic_nonlocal_a_functional	Add nonlocal kinetic energy functional of generic type A.
add_perrot_functional	Add Perrot kinetic energy functional.
add_smargiassi_madden_functional	Add Smargiassi-Madden kinetic energy functional.
add_thomas_fermi_functional	Add Thomas-Fermi kinetic energy functional.
add_wang_teter_functional	Add Wang-Teter kinetic energy functional.
add_wang_govind_carter_functional	Add Wang-Govind-Carter kinetic energy functional (density-dependent kernel).
add_wang_govind_carter_1999_i_functional	Add Wang-Govind-Carter functional (density-independent kernel).
add_weizsaecker_functional	Add Weizsaecker kinetic energy functional.

Electrostatic

add_hartree_functional	Add Hartree functional.
add_ion_electron_functional	Add ion-electron interaction functional.
add_ion_ion_interaction	Add ion-ion interaction energy.

Exchange-correlation

add_libxc_functional	Add libxc exchange-correlation functional.
add_perdew_burke_ernzerhof_functional	Add Perdew-Burke-Ernzerhof generalized gradient approximation exchange-correlation functional.
add_perdew_zunger_functional	Add local density approximation functional, Perdew-Zunger parameterization.

System complete

After building the system, the usual next step is to find the ground state with minimize_energy().

One may then inspect the system, computing or reporting important properties, or modify the system, such as by moving the ions.