[Ifeffit] core hole lifetime in XANES calculation using FEFF82

Dear all, Feff82 uses the data from K. Rahkonen and K. Krause (Atomic Data and Nuclear Data Tables, Vol 14, Number 2, 1974) to set core hole lifetime(gamach parameter). My question is if people can set gamach parameter in Feff82 by themselves? may I use a minus vi0 in EXCHANGE card to reduce broading caused by core hole lifetime? Thanks in advance. Qi