Newman's identity and infinite families of congruences modulo 7 for broken 3-diamond partitions

In 2007, Andrews and Paule introduced the notion of broken k-diamond partitions. Let Delta(k)(n) denote the number of broken k-diamond partitions of n for a fixed positive integer k. Recently, Paule and Radu presented some conjectures on congruences modulo 7 for Delta(3)(n) which were proved by Jameson and Xiong based on the theory of modular forms. Very recently, Xia proved several infinite families of congruences modulo 7 for Delta(3)(n) using theta function identities. In this paper, many new infinite families of congruences modulo 7 for Delta(3)(n) are derived based on an identity of Newman and the (p; k)-parametrization of theta functions due to Alaca, Alaca and Williams. In particular, some non-standard congruences modulo 7 for Delta(3)(n) are deduced. For example, we prove that for alpha >= 0, Delta(3) (14x757(alpha)+1/3) equivalent to 6 - alpha (mod 7).