▁with ▁Ron ald ▁Ny holm ▁( and ▁thus ▁is ▁also ▁known ▁as ▁the ▁G illes pie - N y holm ▁theory ), ▁and ▁setting ▁the ▁rules ▁for ▁assigning ▁numbers . ▁He ▁has ▁written ▁several ▁books ▁on ▁this ▁V SE PR ▁topic ▁in ▁chem istry . ▁With ▁other ▁workers ▁he ▁developed ▁L CP ▁theory , ▁( lig and ▁close ▁pack ing ▁theory ), ▁which ▁for ▁some ▁mole cules ▁allows ▁geometry ▁to ▁be ▁predicted ▁on ▁the ▁basis ▁of ▁lig and - lig and ▁rep uls ions . ▁G illes pie ▁has ▁also ▁done ▁extensive ▁work ▁on ▁interpre ting ▁the ▁c oval ent ▁radius ▁of ▁flu or ine . ▁The ▁c oval ent ▁radius ▁of ▁most ▁atoms ▁is ▁found ▁by ▁taking ▁half ▁the ▁length ▁of ▁a ▁single ▁bond ▁between ▁two ▁similar ▁atoms ▁in ▁a ▁neutral ▁mole c ule . ▁Calcul ating ▁the ▁c oval ent ▁radius ▁for ▁flu or ine ▁is ▁more ▁difficult ▁because ▁of ▁its ▁high ▁electron eg ativity ▁compared ▁to ▁its ▁small ▁atomic ▁radius ▁size . ▁G illes pie ' s ▁work ▁on ▁the ▁bond ▁length ▁of ▁flu or ine ▁focus es ▁on ▁theoret ically ▁determ ining ▁the ▁c oval ent ▁radius ▁of ▁flu or ine ▁by ▁exam ining ▁its ▁c oval ent ▁radius ▁when ▁it ▁is ▁attached ▁to ▁several ▁different ▁atoms . ▁ ▁Publications ▁ ▁Chem ical ▁Bond ing ▁and ▁M ole cular ▁Ge ometry : ▁From ▁Lewis ▁to ▁Electron ▁D ens ities ▁( Top ics ▁in ▁In organ ic ▁Chem istry ) ▁by ▁Ron ald ▁J . ▁G illes pie ▁and ▁Paul