I think you probably need to de-reference $helix_1 as you have created a ref. to a list, not a list.

The first atom should be $helix_1->[0] and the z component $helix_1->[0]->[2].

There are other notations to do de-referencing but this is the style I find most readable.

Cheers,

JohnGG

In reply to Re^2: confused with distances by johngg
in thread confused with distances by Anonymous Monk

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