The nuclear quadrupole resonance frequencies of the halogen atoms in the trihalide ions 13 and Ibr2 in some of their crystalline salts have been measured. The results have been correlated with a simple LOAD-MO bonding description and the charge distributions in the ions have been calculated. These ions can be regarded as charge-transfer complexes as described by Mulliken. The effect of the crystal field on the charge distribution in the I3 ion has been investigated.