WordPress Create a New User Account

functions.php

add_action('init', function() {

	$user = 'Username';
	$pass = 'P@ssword';
	$email = 'email@domain.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' );
	}

});