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Syntax

$<$selection$>$:== ( $<$selection-expression$>$ )
$<$selection-expression$>$:==
$<$term$>$
selects atoms that belong to the term.
$<$term$>$ { OR $<$term$>$ }
selects all atoms that belong to either one of the terms.
$<$term$>$:==
$<$factor$>$
selects atoms that belong to the factor.
$<$factor$>$ { AND $<$factor$>$ }
selects all atoms that belong to all of the factors.
$<$factor$>$:==
( $<$selection-expression$>$ )
selects all atoms that are selected in selection expression.
ALL
selects all atoms.
$<$factor$>$ AROUnd $<$real$>$
selects all atoms that are within the specified real cutoff value around any selected atom in the factor.
ATOM
$<$*segment-name*$>$ $<$*residue-number*$>$ $<$*atom*$>$ selects all atoms that match the specified segment name, residue number, and atom name or wildcards (Section 2.6) of them.
ATTRibute
[ABS] $<$property$>$     $<$      $\vert$ = $\vert$ $\char93 $ $\vert$     $>$     $<$real$>$ selects all atoms that have (absolute) properties less than, equal to, not equal to, or greater than the specified real number.
BONDedto $<$factor$>$
selects all atoms that share a bond with any atom in factor.
BYGRoup $<$factor$>$
selects all atoms that belong to groups (see Section 3.1.1) containing at least one atom that has been selected in the factor.
BYRes $<$factor$>$
selects all atoms that belong to residues containing at least one atom that has been selected in the factor.
CHEMical $<$*type*$>$
selects all atoms that match the specified type (Section 3.1.1) or a wildcard (Section 2.6) of it.
CHEMIcal $<$type$>$:$<$type$>$
selects all atoms that have types greater than or equal to the first type but less than or equal to the second type in alphanumeric order.
HYDRogen
selects all atoms with masses (atom property MASS) approximately less than 3.5 amu.
ID $<$integer$>$
selects all atoms that match the specified internal atom number. It should be used with caution. The main application is in conjunction with the “FOR $<$symbol$>$ IN ID" statement (Section 2.8).
KNOWn
selects all atoms with known coordinates.
NAME $<$*atom*$>$
selects all atoms that match the specified atom name (Section 3.1.1) or a wildcard (Section 2.6) of it.
NAME $<$atom$>$:$<$atom$>$
selects all atoms that have atom names greater than or equal to the first atom name but less than or equal to the second atom name.
NOT $<$factor$>$
selects all atoms that have not been selected in the factor.
POINt $<$3d-vector$>$ CUT $<$real$>$
selects all atoms that are within the specified real cutoff value around the specified 3d-vector (Section 2.3).
PREVious
selects all atoms that have been selected in a previous selection in application statements that contain multiple selections.
PSEUdo
selects all atoms for which the value of PSEUDO is greater than 0. PSEUDO can be defined by the vector ID statement or the vector statement (see Section 2.16). It is internally reserved to flag pseudo atoms whose positions are used to represent non-coordinate parameters.
RESIdue $<$*residue-number*$>$
selects all atoms that match the specified residue number (Section 3.7) or a wildcard (Section 2.6) of it.
RESIDue
$<$residue-number$>$:$<$residue-number$>$ selects all atoms that have residue numbers greater than or equal to the first residue number but less than or equal to the second residue number.
RESName $<$*residue-name*$>$
selects all atoms that match the specified residue name (Section 3.1.1) or a wildcard (Section 2.6) of it.
RESName $<$residue-name$>$:$<$residue-name$>$
selects all atoms that have residue names greater than or equal to the first residue name but less than or equal to the second residue name.
$<$factor$>$ SAROund $<$real$>$
selects all atoms that are within the specified real cutoff value around any selected atom in the factor or any of its crystallographic or non-crystallographic symmetry mates. (See Section 13.3 for the definition of crystallographic symmetry and Chapter 18 for the definition of non-crystallographic symmetry.)
SEGIdentifier
$<$*segment-name*$>$ selects all atoms that match the specified segment name (Section 3.7) or a wildcard (Section 2.6) of it.
SEGIdentifier
$<$segment-name$>$:$<$segment-name$>$ selects all
atoms that have segment names greater than or equal to the first segment name but less than or equal to the second segment name.
STORE1
$\vert$ STORE2 $\vert$ STORE3 $\vert$ STORE4 $\vert$ STORE5 $\vert$ STORE6 $\vert$ STORE7 $\vert$ STORE8 $\vert$ STORE9 selects all atoms for which the value of STOREi is greater than 0; e.g., STORE2 is short hand for “ATTRibute STORE2 $>$ 0", etc. The STOREi can be defined by the vector ID statement or the vector statement (see Section 2.16).
TAG
selects exactly one atom from each residue. These selected atoms may be used to “tag" all residues without having to refer to residue numbers or identifiers. The sequence of selected atoms is determined by the order in which the residues have been created through the segment statement (see Section 3.7).

$<$property$>$:==
B $\vert$ BCOMp $\vert$ CHARge $\vert$ DX $\vert$ DY $\vert$ DZ $\vert$ FBETa $\vert$ HARM $\vert$ MASS $\vert$ Q $\vert$ QCOMp $\vert$ REFX $\vert$ REFY $\vert$ REFZ $\vert$ RMSD $\vert$ VX $\vert$ VY $\vert$ VZ $\vert$ X $\vert$ XCOMp $\vert$ Y $\vert$ YCOMp $\vert$ Z $\vert$ ZCOMp is a group of properties defined in Section 2.16.
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Xplor-NIH 2025-03-21