ezff.utilities.reaxff - Utility to generate forcefield templates for ReaxFF

class ezff.utils.reaxff.reax_forcefield(filename=None, filestring=None, template='ff.template.generated', ranges='param_ranges', bo_threshold=1e-08)

ReaxFF forcefield class. Used for generating ReaxFF templates

generate_templates()

Function to write-out the current modified forcefield sections into a forcefield template file

make_template_fourbody(e1, e2, e3, e4, bounds=0.1, common=False)

Function to generate decision variables for all four-body terms for a given quartet of elements

Parameters:

• e1 (str) – Chemical symbol for element 1
• e2 (str) – Chemical symbol for element 2
• e3 (str) – Chemical symbol for element 3
• e4 (str) – Chemical symbol for element 4
• bounds (float) – Maximum deviation allowed for each decision variable from its current value in the forcefield
• common (bool) – Flag for the optimization of common parameters

make_template_qeq(e1, bounds=0.1)

Function to generate decision variable for Charge Equilibration (QEq) terms

: param e1 : Chemical symbol for element 1 : type e1 : str

: param bounds: Maximum deviation allowed for each decision variable from its current value in the forcefield : type bounds: float

make_template_threebody(e1, e2, e3, bounds=0.1, common=False)

Function to generate decision variables for all three-body terms for a given triplet of elements

Parameters:

• e1 (str) – Chemical symbol for element 1
• e2 (str) – Chemical symbol for element 2
• e3 (str) – Chemical symbol for element 3
• bounds (float) – Maximum deviation allowed for each decision variable from its current value in the forcefield
• common (bool) – Flag for the optimization of common parameters

make_template_twobody(e1, e2, double_bond=False, triple_bond=False, bounds=0.1, common=False)

Function to generate decision variables for all two-body terms (i.e. bond-order, attractive and vdW) between two given elements

Parameters:

• e1 (str) – Chemical symbol for element 1
• e2 (str) – Chemical symbol for element 2
• bounds (float) – Maximum deviation allowed for each decision variable from its current value in the forcefield
• double_bond (bool) – Flag for the presence of a double-bond between elements e1 and e2
• triple_bond (bool) – Flag for the presence of a triple-bond between elements e1 and e2
• common (bool) – Flag for the optimization of common parameters

read_forcefield_from_file(filename)

Read ReaxFF forcefield from external file

Parameters:filename (str) – ReaxFF forcefield filename

read_forcefield_from_string(filestring)

Read ReaxFF forcefield from a given forcefield string

Parameters:filestring (str) – ReaxFF forcefield string

write_formatted_forcefields()

Function to write-out the current forcefield with correct ReaxFF formatting

Parameters:outfilename (str) – File to which formatted forcefield to be written to

write_gulp_library(outfilename=None)

Function to write-out the forcefield in the GULP library format

Parameters:outfilename (str) – File to which the GULP ReaxFF forcefield library