Is there a canonical metric for a Lie group manifold?

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A Lie group can be defined as a differentiable manifold. Is it possible to import the notion of Riemannian metric on differentiable manifolds to define a canonical metric on a Lie group?

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  1. Each compact connected simple Lie group has a unique (up to scalar) biinvariant Riemannian metric.

  2. Every Lie group $G$ admits a (canonical) finite-dimensional family of left-invariant Riemannian metrics. The space of this metrics is parameterized by the space of congruence classes of positive-definite quadratic forms on $R^n$ ($n=dim(G)$).

  3. If $G$ is a simple Lie group with a maximal compact subgroup $K$ then $G$ admits a unique (up to scalar) left-invariant Riemannian metric which is right-invariant under $K$. This includes (1) as a special case.