  Finite-temperature structures of Cu, Ag, and Au metal nanoclusters are
calculated in the entire temperature range from 0 K to melting using a
computational methodology that we proposed recently [Settem \emph{et al.},
Nanoscale, 2022, 14, 939]. In this method, Harmonic Superposition Approximation
(HSA) and Parallel Tempering Molecular Dynamics (PTMD) are combined in a
complementary manner. HSA is accurate at low temperatures and fails at higher
temperatures. PTMD, on the other hand, effectively samples the high temperature
region and melting. This method is used to study the size- and system-dependent
competition between various structural motifs of Cu, Ag, and Au nanoclusters in
the size range 1 to 2 nm. Results show that there are mainly three types of
structural changes in metal nanoclusters depending on whether a solid-solid
transformation occurs. In the first type, global minimum is the dominant motif
in the entire temperature range. In contrast, when a solid-solid transformation
occurs, the global minimum transforms either completely to a different motif or
partially resulting in a co-existence of multiple motifs. Finally, nanocluster
structures are analyzed to highlight the system-specific differences across the
three metals.
