ataqv is a toolkit for measuring and comparing ATAC-seq results and to make it easier to spot differences that might be caused by library prep or sequencing. The main program, ataqv, examines your aligned reads and reports some basic metrics, including:
reads mapped in proper pairs
optical or PCR duplicates
reads mapping to autosomal or mitochondrial references
the ratio of short to mononucleosomal fragment counts
mapping quality
various kinds of problematic alignments
You can find a brief description with the command
module help ataqv