Type:         Double
  Default:      0.0
  Definition:   Sets the value of the cubic term in the Taylor series expansion form of the bond angle bending potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
This term multiplied by the angle bending energy unit conversion factor, the force constant,
and the cube of the deviation of the bond angle from its ideal value gives the cubic contribution to the angle bending energy.
The default value in the absence of the angle-cubic keyword is zero; i.e., the cubic angle bending term is omitted.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the fifth power term in the Taylor series expansion form of the bond angle bending potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
This term multiplied by the angle bending energy unit conversion factor, the force constant,
and the fifth power of the deviation of the bond angle from its ideal value gives the pentic contribution to the angle bending energy.
The default value in the absence of the angle-pentic keyword is zero; i.e., the pentic angle bending term is omitted.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the quartic term in the Taylor series expansion form of the bond angle bending potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
This term multiplied by the angle bending energy unit conversion factor, the force constant,
and the forth power of the deviation of the bond angle from its ideal value gives the quartic contribution to the angle bending energy.
The default value in the absence of the angle-quartic keyword is zero; i.e., the quartic angle bending term is omitted.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the sixth power term in the Taylor series expansion form of the bond angle bending potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
This term multiplied by the angle bending energy unit conversion factor, the force constant,
and the sixth power of the deviation of the bond angle from its ideal value gives the sextic contribution to the angle bending energy.
The default value in the absence of the angle-sextic keyword is zero; i.e., the sextic angle bending term is omitted.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the cubic term in the Taylor series expansion form of the bond stretching potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
This term multiplied by the bond stretching energy unit conversion factor, the force constant,
and the cube of the deviation of the bond length from its ideal value gives the cubic contribution to the bond stretching energy.
The default value in the absence of the bond-cubic keyword is zero; i.e., the cubic bond stretching term is omitted.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the quartic term in the Taylor series expansion form of the bond stretching potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
This term multiplied by the bond stretching energy unit conversion factor, the force constant,
and the forth power of the deviation of the bond length from its ideal value gives the quartic contribution to the bond stretching energy.
The default value in the absence of the bond-quartic keyword is zero; i.e., the quartic bond stretching term is omitted.

  Type:         Double
  Default:      332.063713
  Definition:   Specifies a value for the so-called "electric constant" allowing conversion unit of electrostatic
potential energy values from electrons^2/Angstrom to kcal/mol. Internally, FFX stores a default value
for this constant as 332.063713 based on CODATA reference values. Since different force fields are
intended for use with slightly different values, this keyword allows overriding the default value.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the cubic term in the Taylor series expansion form of the out-of-plane bending potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
This term multiplied by the out-of-plane bending energy unit conversion factor, the force constant,
and the cube of the deviation of the out-of-plane angle from zero gives the cubic contribution to the out-of-plane bending energy.
The default value in the absence of the opbend-cubic keyword is zero; i.e., the cubic out-of-plane bending term is omitted.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the fifth power term in the Taylor series expansion form of the out-of-plane bending potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
This term multiplied by the out-of-plane bending energy unit conversion factor, the force constant,
and the fifth power of the deviation of the out-of-plane angle from zero gives the pentic contribution to the out-of-plane bending energy.
The default value in the absence of the opbend-pentic keyword is zero; i.e., the pentic out-of-plane bending term is omitted.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the quartic term in the Taylor series expansion form of the out-of-plane bending potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
This term multiplied by the out-of-plane bending energy unit conversion factor, the force constant,
and the forth power of the deviation of the out-of-plane angle from zero gives the quartic contribution to the out-of-plane bending energy.
The default value in the absence of the opbend-quartic keyword is zero; i.e., the quartic out-of-plane bending term is omitted.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the sixth power term in the Taylor series expansion form of the out-of-plane bending potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
This term multiplied by the out-of-plane bending energy unit conversion factor, the force constant,
and the sixth power of the deviation of the out-of-plane angle from zero gives the sextic contribution to the out-of-plane bending energy.
The default value in the absence of the opbend-sextic keyword is zero; i.e., the sextic out-of-plane bending term is omitted.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the cubic term in the Taylor series expansion form of the Urey-Bradley potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
The default value in the absence of the urey-cubic keyword is zero; i.e., the cubic Urey-Bradley term is omitted.

  Type:         Double
  Default:      0.0
  Definition:   Sets the value of the quartic term in the Taylor series expansion form of the Urey-Bradley potential energy.
The real number modifier gives the value of the coefficient as a multiple of the quadratic coefficient.
The default value in the absence of the urey-quartic keyword is zero; i.e., the quartic Urey-Bradley term is omitted.