Section BEND

• Specifies the bend potential of the MM system.

• Section path: CP2K_INPUT / FORCE_EVAL / MM / FORCEFIELD / BEND

• This section can be repeated.

• Subsections

  • UB

• Keywords

  • ATOMS
  • CB
  • K
  • KBS12
  • KBS32
  • KIND
  • KSS
  • R012
  • R032
  • THETA0

• Keyword descriptions

  ATOMS
  	ATOMS {Word} {Word} {Word}
  	Defines the atomic kinds involved in the bend.
  	This keyword cannot be repeated and it expects precisely 3 words.

  CB
  	CB {Real}
  	Defines the the cubic force constant of the bend
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+00
  	Default unit: [rad^-1]

  K
  	K {Real}
  	Defines the force constant of the potential
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [rad^-2*hartree]

  KBS12
  	KBS12 {Real}
  	Mixed bend stretch parameter
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+00
  	Default unit: [rad^-1*bohr^-1*hartree]

  KBS32
  	KBS32 {Real}
  	Mixed bend stretch parameter
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+00
  	Default unit: [rad^-1*bohr^-1*hartree]

  KIND
  	KIND {Keyword}
  	Define the kind of bend potential
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: CHARMM
  	List of valid keywords: AMBER Functional Form (CHARMM|AMBER): K*(THETA-THETA0)^2 CHARMM Functional Form (CHARMM|AMBER): K*(THETA-THETA0)^2 CUBIC Functional Form (CUBIC): K*(THETA-THETA0)**2*(1+CB*(THETA-THETA0)) G87 Functional Form (HARMONIC|G87): 1/2*K*(THETA-THETA0)^2 G96 Functional Form (G96): 1/2*K*(COS(THETA)-THETA0)^2 HARMONIC Functional Form (HARMONIC|G87): 1/2*K*(THETA-THETA0)^2 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) MM3 Functional Form (MM3): 1/2*K*(THETA-THETA0)**2*(1-0.014*(THETA-THETA0)+5.6E-5*(THETA-THETA0)**2 -7.0E-7*(THETA-THETA0)**3+9.0E-10*(THETA-THETA0)**4)+KBS12*(R12-R012)*(THETA-THETA0)+ KBS32*(R32-R032)*(THETA-THETA0)

  KSS
  	KSS {Real}
  	Mixed bend stretch parameter
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+00
  	Default unit: [bohr^-2*hartree]

  R012
  	R012 {Real}
  	Mixed bend stretch parameter
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+00
  	Default unit: [bohr]

  R032
  	R032 {Real}
  	Mixed bend stretch parameter
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+00
  	Default unit: [bohr]

  THETA0
  	THETA0 {Real}
  	Defines the equilibrium angle.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [rad]