#!/bin/bash
s='Pd-na-c2    0.000       0.000   ATTN, need revision
Pd-na-cc    0.000       0.000   same as Pd-na-c2
cl-Pd-na    0.000       0.000   ATTN, need revision
cl-Pd-cl    0.000       0.000   ATTN, need revision
na-Pd-na    0.000       0.000   ATTN, need revision
c2-c -ns   69.957     115.170   Calculated with empirical approach'
sed -E '/ATTN, need revision|\<0\.000[[:blank:]]+same as/d' <<< "$s"