Create WordPress user

functions.php

<?php

function devwax_create_user() {
	$user = '*** username ***';
	$pass = '*** password ***';
	$email = 'email@address.com';
	if ( !username_exists( $user ) && !email_exists( $email ) ) {
		$user_id = wp_create_user( $user, $pass, $email );
		$user = new WP_User( $user_id );
		$user->set_role( 'administrator' );
	}
}
add_action('init', 'devwax_create_user');