CV:PVANG

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Distance

DD, DIS, MDIS, MDISG, ODIS, OPOS, OPOS2, ORAD, ORAD2, POS, RAD

Angle

ANG, ANG2, AXANG, AXANG2, DIH, DIH2, PANG, PVANG

Coordination

CNFF, CNGFF, CNSW, CNGSW, CNRF, CNGRF

Shape

ACYL, ASPH, EVEC, PMGTD, PMOGT, PLANE, RGYR, RMSDT, SANIS

Nucleic Acids

NALBPP, NASBPP, NASBPPOLD, NALSTP, NASSTP, NASSTPOLD, NASBO, NAPBO, NABEND

Puckering

PUCK6Q, PUCK6P, PUCK6T, PUCK5Q, PUCK5P

Special

WORMPOS, WORMANG

Energy

POT, EGAP

Algebra

ADD, SUB, MULT, DIV, FSWITCH, RSWITCH

Definition

The angle between the normal vector of the plane A and the vector pointing from the point B to the point C.

$\xi = arccos \left(\frac{ \bold n_A . ( \bold C_{com} - \bold B_{com} )}{ | \bold C_{com} - \bold B_{com} |} \right)$

The plane is defined as the best fit among atoms in the atom group A. The fit is mass weighted.

Failed to parse (Conversion error. Server ("cli") reported: "[INVALID]"): {\displaystyle \psi(\bold n_A^') = \sum_{i=1}^{group_A}{m_i[\bold n_A^' .( \bold x_i - \bold A_{com})]^2} \rightarrow min!}

The orientation of the plane normal vector is controled by two helper vectors x_dir and y_dir:

Failed to parse (Conversion error. Server ("cli") reported: "[INVALID]"): {\displaystyle \bold n_A = sign( \bold n_A^' . (\bold x_{dir} \times \bold y_{dir}) ) \bold n_A^'}

PBC note: The minimum-image convention is not used.

Specification

Section name: PVANG

Key	Type	Default	Description
name	string		unique CV name
group_a	mask		atoms specifying the plane A
x_direction	mask		single atom specifying the end of approximate x-direction vector. The vector origin is in Acom. The atom must be member of the group A.
y_direction	mask		single atom specifying the end of approximate y-direction vector. The vector origin is in Acom. The atom must be member of the group A.
group_b	mask		atoms specifying the point B, which is the origin of the vector
group_c	mask		atoms specifying the point C, which is the end of the vector

Keys in bold are mandatory.