%chk=bcl3_nbo.chk
%mem=200MB
%nproc=1
# b3lyp/3-21g pop=nboread test

Title Card Required

0 1
 5         .000000     .000000     .000000
17         .000000    1.775028     .000000
17        1.537220    -.887514     .000000
17       -1.537220    -.887514     .000000

$NBO nbo resonance nbosum nlmo npa nrt $END
$CHOOSE
  ALPHA
    LONE 2 3 3 3 4 3 END
    BOND S 1 2 S 1 3 S 1 4 END
  END
  BETA
    LONE 2 3 3 3 4 3 END
    BOND S 1 2 S 1 3 S 1 4 END
  END
$END