TABLE OF CONTENTS

::pwtk::pwi::getPrimVec

SYNOPSIS

proc ::pwtk::pwi::getPrimVec {} {

PURPOSE

Get lattice vectors from the pw.x input data (in alat units), i.e.: 

        ax ay az
        bx by bz
        cx cy cz

If ibrav == 0 (no CELL_PARAMETERS card) an empty string is returned.

SOURCE

    set vec [::pwtk::input::cardGetContent CELL_PARAMETERS]
    
    set nl ""
    foreach line [split $vec \n] {

        # check for syntax correctness

        set len [llength $line]

        if { $len == 3 } {
            append new_vec ${nl}${line}
            set nl "\n"
        } elseif { $len > 0 } {
            # it's not an empty line -> SYNTAX error
            pwtk::error "syntax error in CELL_PARAMETERS card, line = $line"
        }
    }
    return $new_vec
}