jQuery(function($){

    var $container = $('.related-posts-list')
    // initialize Isotope
    $container.isotope({
        // options...
        resizable: false, // disable normal resizing
        // set columnWidth to a percentage of container width
        masonry: { columnWidth: $container.width() / 4 }
    });

    // update columnWidth on window resize
    $(window).smartresize(function(){
        $container.isotope({
            // update columnWidth to a percentage of container width
            masonry: { columnWidth: $container.width() / 4 }
        });
    });

});