  Mn$_3$Sn has garnered significant attention due to its kagome lattice,
120$^\circ$ noncollinear antiferromagnetic order, and substantial anomalous
Hall effect. In this study, we comprehensively explore intrinsic and extrinsic
contributions to anomalous Hall, anomalous Nernst, and anomalous thermal Hall
effects, employing first-principle calculations and group theory analysis.
Comparative analysis between our theoretical results and available experimental
data underscores the predominance of intrinsic mechanism in shaping anomalous
transport properties at low temperatures. Specifically, Weyl fermions are
identified as the primary contributors to intrinsic anomalous Hall
conductivity. The significance of extrinsic mechanisms becomes evident at high
temperatures, especially when the longitudinal charge conductivity falls into
the dirty regime, where the side jump mechanism plays a vital role. Extrinsic
contributions to anomalous transport properties are primarily influenced by the
electronic states residing at the Fermi surfaces. Furthermore, anomalous
transport properties exhibit periodic variations when subjected to spin
rotations within the kagome plane, achievable by applying an external magnetic
field. Our findings advance the understanding of anomalous transport phenomena
in Mn$_3$Sn and offer insights into potential applications of noncollinear
antiferromagnetic materials in spintronics and spin caloritronics.
