The CP2K project : input section BEND

Section BEND

Index of all sections. This section is located at __ROOT__%FORCE_EVAL%MM%FORCEFIELD%BEND.

Specifies the bend potential of the MM system. This section can be repeated and can not be optional.

Subsections

Section keywords

Keyword descriptions

ATOMS
ATOMS {KIND1} {KIND2} {KIND3}
Defines the atomic kinds involved in the bend.
This required keyword expects precisely 3 words
KIND
KIND HARMONIC
Define the kind of bend potential
This optional keyword expects a keyword. Default value: CHARMM
valid keywords:
  • HARMONIC: Functional Form (HARMONIC|G87): 1/2*K*(THETA-THETA0)^2
  • CHARMM: Functional Form (CHARMM|AMBER): K*(THETA-THETA0)^2
  • AMBER: Functional Form (CHARMM|AMBER): K*(THETA-THETA0)^2
  • G87: Functional Form (HARMONIC|G87): 1/2*K*(THETA-THETA0)^2
  • G96: Functional Form (G96): 1/2*K*(COS(THETA)-THETA0)^2
  • CUBIC: Functional Form (CUBIC): K*(THETA-THETA0)**2*(1+CB*(THETA-THETA0))
  • MIXED_BEND_STRETCH: Functional Form (MIXED_BEND_STRETCH): K*(THETA-THETA0)**2*(1+CB*(THETA-THETA0))+ KSS*(R12-R012)*(R32-R032)+KBS12*(R12-R012)*(THETA-THETA0)+KBS32*(R32-R032)*(THETA-THETA0)
K
K {real}
Defines the force constant of the potential
This required keyword expects a real. Default unit: [rad^-2hartree].
CB
CB {real}
Defines the the cubic force constant of the bend
This optional keyword expects a real. Default unit: [rad^-1], default value: 0.0000000000000000E+00 rad^-1
R012
CB {real}
Mixed bend stretch parameter
This optional keyword expects a real. Default unit: [bohr], default value: 0.0000000000000000E+00 bohr
R032
CB {real}
Mixed bend stretch parameter
This optional keyword expects a real. Default unit: [bohr], default value: 0.0000000000000000E+00 bohr
KBS12
CB {real}
Mixed bend stretch parameter
This optional keyword expects a real. Default unit: [rad^-1bohr^-1hartree], default value: 0.0000000000000000E+00 rad^-1bohr^-1hartree
KBS32
CB {real}
Mixed bend stretch parameter
This optional keyword expects a real. Default unit: [rad^-1bohr^-1hartree], default value: 0.0000000000000000E+00 rad^-1bohr^-1hartree
KSS
CB {real}
Mixed bend stretch parameter
This optional keyword expects a real. Default unit: [bohr^-2hartree], default value: 0.0000000000000000E+00 bohr^-2hartree
THETA0
THETA0 {real}
Defines the equilibrium angle.
This required keyword expects a real. Default unit: [rad].


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