Struct DFTD3ZeroDampingParam 

pub struct DFTD3ZeroDampingParam {
    pub s6: f64,
    pub s8: f64,
    pub s9: f64,
    pub rs6: f64,
    pub rs8: f64,
    pub alp: f64,
}

Original DFT-D3 damping function with variant.

Original DFT-D3 damping function ¹, based on a variant proposed by Chai and Head-Gordon ². Since it is damping the dispersion energy to zero at short distances it is usually called zero damping scheme for simplicity. However, due to this short-range limit of the dispersion energy a repulsive contribution to the gradient can arise, which is considered artificial ³.

Common API documentation for custom damping parameter specification

If your task is to retrive damping parameters of some specific xc-functionals, you may wish to try dftd3_load_param function.

In this crate, you may have three ways to define customized parameters:

• By DFTD3***DampingParam struct. In this way, all parameters (include optional parameters with default value) must be provided. For example of B3-Zero:

  let param = DFTD3ZeroDampingParam {
      s6: 1.0,
      s8: 1.683,
      rs6: 1.139,
      rs8: 1.0,
      alp: 14.0,
      s9: if atm { 1.0 } else { 0.0 },
  };
  let param = param.new_param();
  // this will give param: DFTD3Param

• By DFTD3***DampingParamBuilder struct. In this way, optional parameters can be omitted. For example of B3-Zero:

  let param = DFTD3ZeroDampingParamBuilder::default()
      .s8(1.683)
      .rs6(1.139)
      .s9(if atm { 1.0 } else { 0.0 })
      .init();
  // this will give param: DFTD3Param

• By DFTD3Param utility. In this way, all parameters must be provided. For example of B3-Zero:

  let param = DFTD3Param::new_zero_damping(
      1.0,                         // s6
      1.683,                       // s8
      if atm { 1.0 } else { 0.0 }, // s9
      1.139,                       // rs6
      1.0,                         // rs8
      14.0,                        // alp
  );

Please note that different DFT-D3 versions may have different parameters, for example modified zero damping have another parameter bet for beta, and rational damping (D3-BJ) have parameter name a1, a2 instead of rs6, rs8.

---

1. S. Grimme, J. Antony, S. Ehrlich, and H. Krieg. A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu. J. Chem. Phys., 132:154104, 2010. doi: 10.1063/1.3382344. ↩

2. Chai, J.-D.; Head-Gordon, M. Long-range corrected hybrid density functionals with damped atom–atom dispersion corrections. Phys. Chem. Chem. Phys., 2008, 10(44), 6615–6620. doi: 10.1039/B810189B. ↩

3. Grimme, S.; Ehrlich, S.; Goerigk, L. Effect of the damping function in dispersion corrected density functional theory. J. Comput. Chem., 2011, 32, 1456–1465. doi: 10.1002/jcc.21759. ↩

Fields

s6: f64

optional, default 1.0

s8: f64

s9: f64

optional, default 1.0

rs6: f64

rs8: f64

optional, default 1.0

alp: f64

optional, default 14.0

Trait Implementations

impl Clone for DFTD3ZeroDampingParam

fn clone(&self) -> DFTD3ZeroDampingParam

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl DFTD3LoadParamAPI for DFTD3ZeroDampingParam

fn load_param_f(method: &str, atm: bool) -> Result<DFTD3Param, DFTD3Error>

fn load_param(method: &str, atm: bool) -> DFTD3Param

impl DFTD3ParamAPI for DFTD3ZeroDampingParam

fn new_param_f(self) -> Result<DFTD3Param, DFTD3Error>

fn new_param(self) -> DFTD3Param

where Self: Sized,

impl Debug for DFTD3ZeroDampingParam

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.