DescriptorsCalc

template<typename D2 = tadah::models::D2_Base&, typename DM = tadah::models::DM_Base&, typename C2 = tadah::models::Cut_Base&, typename CM = tadah::models::Cut_Base&> class DescriptorsCalc : public tadah::mlip::DC_Base

Descriptors calculator.

This object does not store any data.

Usage example:

# Build calculator using tadah::core::Context object.
DescriptorsCalc<D2_LJ, DM_Dummy> dc(context);

# Calculate all descriptors in a Structure st
StDescriptors std = dc.calc(st);

# Calculate all descriptors in a StructureDB st_db
StDescriptorsDB std_db = dc.calc(st_db);

This object sets the following INTERNAL_KEYS to the provided tadah::core::Context object:

SIZE2B,SIZE3B,SIZEMB,DSIZE

Required keys: INIT2B,INIT3B,INITMB, RCUT2B,RCUT3B,RCUTMB (for initialised ones)

Template Parameters:

D2 – D2_Base child, two-body type calculator.
DM – DM_Base child, many-body type calculator.
C2 – Cut_Base child, two-body cutoff function.
CM – Cut_Base child, many-body cutoff function.

Public Functions

DescriptorsCalc(tadah::core::Context &c)

Constructor to fully initialise this object.

REQUIRED context KEYS: FORCE, STRESS, at least one of: RCUT2B, RCUT3B,RCUTMB

template<typename T1, typename T2, typename T3, typename T4> DescriptorsCalc(tadah::core::Context &c, T1 &d2, T2 &dm, T3 &c2, T4 &cm)

This constructor is equivalent to the main constructor above.

The difference is technical in nature. Here we use OOP with generic programming to call virtual functions to calculate descriptors - this incurs small efficiency penalty but makes selecting of descriptors somewhat easier at runtime.

In contrast, the main constructor above is purely generic.

The rule of thumb is: Use the main contructor unless it’s a pain.

Usage example:

# Build calculator using tadah::core::Context object.
D2_Base *d2 = new D2_LJ(context);
D2_Base *dm = new DM_Dummy(context);
DescriptorsCalc<> dc(context, d2, dm);

# Calculate all descriptors in a Structure st
StDescriptors std = dc.calc(st);

# Calculate all descriptors in a StructureDB st_db
StDescriptorsDB std_db = dc.calc(st_db);

Warning

{ The unfortunate consequence is that you might want to try this

DescriptorsCalc<> dc(context);

Basically you are trying to init abstract classes with context object. It won’t compile! }

virtual StDescriptors calc(const Structure &st) const: Calculate all descriptors in a Structure st

virtual StDescriptorsDB calc(const StructureDB &st_db) const: Calculate all descriptors in a StructureDB st_db

void calc_rho(const Structure &st, StDescriptors &std) const: Calculate density vector for the structure