Department of Chemistry and Green-Nano Materials Research Center, College of Natural Sciences, Kyungpook National University, Sangyeok, Bukgu, Daegu 702-701, South Korea. *E-mail: email@example.com
Reduced dimensional umbrella sampling (RDUS) has been introduced to describe the free energy surface of multi-dimensional reaction paths. It is a simple and efficient method to reduce multidimensional space by sampling along the reaction path between the reactant and product internal modes. The RDUS technique has been applied to two multidimensional reactions; double proton transfer of acetic acid dimer and hydrolysis of methyl diazonium ion. Free energy surfaces of those reaction paths have been examined by quantum mechanics/molecular mechanics molecular dynamics (QM/MM-MD) in combination with RDUS technique. It has been proved that the RDUS technique effectively demonstrated the free energy surface of those reactions with one-dimensional reaction coordinate.